AC has tested the GP5000 1.4W faster aerodynamically than the Corsa speed (as a full slick) at 45kph:
The 25mm Veloflex Record are 1.5W faster than GP5000TT at the same speed. So it really is a wash…
Until you go 2020 23mm Record, that are another 2W faster rolling per tire.
I don’t think anyone will ever win or lose a race because of 0.1W 
As far as new TT bikes that are fast and have adjustable stem and handlebars there aren’t many options. I attribute this to the additional weight of disc brakes, which has probably force designers toward a one piece base bar and stem. The reach adjustment has then been built into the aero bar by allowing movable pads and extensions. About the only bike I can think of with a standard stem would be a Quintana Roo and those tend to lower-end models.
If you can live without the standard stem, and you want all the good stuff like top end aero, storage, disc brakes, and an adjustable cockpit, then all the new bikes from the major brands probably. P5, Speed Concept and Speedmax appeal to me.
The Shiv Disc has a standard headset/stem as well.
My setup is cervelo p series with tririg bars. I already had the other pieces so it ended up being $3500 at the time. It doesn’t get more adjustable then that. It has a small amount of storage built in.
So I know TT skinsuits are very individual and I can only know which one is the best by trying out multiple ones and aero testing them. But having averaged 46.3km/h on 315W at a recent local time trial with a relatively basic setup and just a short sleeved trisuit, taking 3rd place overall, I want to take my TT’ing to the next step and one of those is a good long sleeved skinsuit (with shoe covers and perhaps gloves even).
I’ve looking into a few options and I’m looking for people’s experiences with those suits.
I had a No Pinz skin suit for a couple of years and got quite good for me results even after I put a few holes in it but I can’t really compare it to anything else. With the holes my best result in the NoPinz was a 56.59 for a 25miles TT in May 21. Lol, this year my club got new Endura Drag 2 Zero skinsuits, which is a much better fit for me and its supposed to be faster and I should have been able to non scientifically at least compared to that. But on the same 25mile course my best this year 59.16 and at the weekend I was 1:01:49. Whilst I haven’t had the best of luck with the weather, I strongly suspect there’s other things going on. There’s a drop of in power (even though AI FTP doesn’t think so) and motivation but I also suspect that the worn dropouts that were refaced have worn again allowing the wheel to rub against the brakes/frame at times.
I’ve had good results this year in a Nopinz flow suit but i’ve not tested it back to back against anything else. My previous bioracer suit was a few years old and getting a bit baggy, so comparing would have been a waste of time.
I now have a new bioracer one as well so will be able to test them against eachother next year.
i have no experience with the other brands you’ve mentioned.
I have the no pinz flow (long sleeve,) no pinz flow subzero and a velotec. I had the velotec first and is was good, but the chamois wore out quickly. This was a few years ago. I then had the long sleeve flow suit customized to fit because the arms and legs are always too long for me in any skinsuit. I found it to be faster anecdotally than the velotec. I then got the subzero because I have a habit of melting down in 40k TT’s that are over 90 deg F. This suit is supposed to faster than the long sleeve suit across their tested speed range. It’s my primary suit now and it does seem, again anecdotally, quicker, but definitely cooler.
AERO-DATA-SUITS.pdf (293.6 KB)
Interesting. I live in a warm area, so have been interested in giving a short sleeve suit a try. Do you use the subzero with the icepacks?
I don’t, on purpose anyway. because they are slower according to their data. I forgot to take one out I had been using during warm up and ended up racing with it. They don’t last very long, especially in hot weather and since they sit so high on your back, they can interfere slightly with your helmet. I can say that when I ran my numbers back through Best Bike Split for that race, my estimated CdA was high, but I made other subsequent changes to the bike, so I can’t pin it all on the ice pack.
Its honestly a coin toss. All of the ones you listed should be noticeably faster than what you have now. I dont think you will be able to tell a difference between your options outside of a wind tunnel or testing with an expert.
One important thing is fit. I know that you mentioned the Rule 28 suit is above your budget, but I can tell you from experience the custom fit suit from Nopinz will be your best bet. I don’t have the custom one but I have a small and its so tight in the shoulders that it limits my ability to shrug. I think this minor difference is why my club suit generally shows the same cda estimate in races. I also noticed around a 10 watt difference from an old stretched out medium skinsuit and a new small suit. So not too small and not too big seems to be the way to go, and the custom route would be the way to get that right. Given the budget, I would do some sizing research to make sure you are getting something that fits since they are probably slightly different cuts.
I have the last two Nopinz suits and Im leaning towards Rule 28 next because I’ve noticed the base layer concept is being used by a lot of fast riders. I feel like worst case is that I can throw it under my club suit and push ahead of the flow suit. I’m hoping to test all of these one day in a tunnel.
Gloves probably arent worth it. Shoe covers are a definite yes. I generally race with covers or guards that go up to my knees since I dont compete in UCI events.
The other easy upgrades are tires (type and width) and practicing keeping your head low while looking forward on the trainer.
Looks like Princeton has the 9590 and 7580TS up on their consumer site now. 9590 looks to only be available as a (very expensive) set, rather than individual wheels.
The lack of data on their website really help justify the cost…
My thoughts exactly…
bUt iNeOs uSe ThEm!!!
TT Adjacent…but looks like Canyon just released a track version of their Speedmax and is the new bike sponsor for the USA track team.
https://www.instagram.com/reel/CjlPRkqj8kv/?igshid=YmMyMTA2M2Y=
That fire alarm sign is such a dead giveaway that you went to the UK, lol.
But there’s actually a clue in the photo of where you went. Nice!
Surprised UCI did not disqualify you in the middle of testing session due to maximum sock length breach
Looking forward to hear from you about it. As someone who “only” did velodrome testing I wonder how windtunnel testing is compared to it. Please let us know 
