My bike fitter had great things to say about Giant bikes. Im not the biggest fan of planetX as it feels like they just buy ‘open mound’ variants in bulk, brand them and resell with their logos. I could be very wrong here so please take this with a grain of salt. Personally would go with the giant simply on the basis that that brand has more pedigree than the PX ones.
My first carbon bike was a PX (Viner) and i never enjoyed the feel of it on the road the way i do with my Willier. Opening up a can of worms here but probably not a whole load of aero benefit of the PX over the giant considering exposed cables, stock wheels, round tube handlebars etc etc…
That is my understanding of their business model too. They sometimes mention “designing” or “designed” things, but I think that is at most getting a few frames in in different carbon grades/layups, and choosing one. There’s no windtunnel or FEA analysis going on. I’m often tempted by their prices, but know it’s just what I can get form Aliexpress, except it’s painted and comes from a local distributor in case things go wrong.
Got the Felt Breed all decked out to start dabbling in bikepacking. Doing a 100 mile gravel loop and camping at a local lake around the half way point next weekend. Swapped out the WTB Byways for some Conti Race King Protection 27.5 x 2.2. They measure out at 53mm and still have right at 6mm clearance on each side of the chain stays.
Picked up a 2018 Epic on Pinkbike last month; finally got it out for a local race yesterday. Also, first race since starting TR 4 months ago. Placed 7th overall in “Advanced” category. Super stoked! I beat a few locals who were killing me last year.