I’ve been riding an Open UPPER as my do it all bike for the last 1.5 years and have nothing but great praise for the frame. I wanted a bike that would be equally at home running aero wheels and skinny tires as it was ripping gravel and epic bikepacking trips, and my bike has done it all perfectly. It’s primary wheelset is 30mm deep carbon rims running 38mm slick tires, and I have a 650b set running 2.2in treaded tires for bikepacking but I can also throw in my 50mm deep aero wheels from my race bike whenever I want. Swapping between wheelsets takes 2min as I have used shims to line up all the rotors and they all have the same cassette spacing.
I went with the Open after looking at a handful of other frames to build up primarily due to the fact that it had the most “road” like geometry between the bikes I was looking at. I wanted as short of wheelbase and chainstays as possible with low stack so that it wouldn’t feel sluggish on the road. Looks like the Cervelo geometry is pretty damn similar, so I’m sure you can’t go wrong either way. Weight wise, looks like the Open UP will likely be very slightly lighter whereas the UPPER will save a bit more weight but we all know it really will have zero effect on your rides whatsoever! My experience with Open support has been top notch, they are ridiculously fast to answer questions, send spare parts, etc but I have no idea how that compares to Cervelo support.
Honestly, you can’t go wrong with either bike! If I was choosing now I would likely still go with the Open as in my own personal opinion I think it looks better (skinnier tubes & the cable routing on the Aspero has always sorta bugged me) but from a ride quality perspective I feel like both bikes will be super similar.