I'll wade in here as the aforementioned PXPC owner that Shamrock mentions.
My experience has been overwhelmingly positive. I got mine on the cycle to work scheme, I think it was costing a shade over £50 a month or something - throw away cash, far less than I boozed away each month anyway. Perspective.
As for the ride, I've had mine for about 7000 miles. The bike has been ridden in all conditions, wet/dry, around Alpe d'Huez and the UK.
The frame is responsive and accelerates well. There is a noticeable difference in the pickup between the PX compared to my Trek 1.2 commuter.
I'm not a particularly powerful rider, it doesn't suit my build, far more of a spinner. I can't say that i've noticed any particular flex from the frame in that respect. Mostly I find the ride pretty comfortable. I suspect I could upgrade the seatpost / handlebars and bar tape if I found it harsh.
With a good wheelset and ultegra it's a really decent budget ride.
Can't comment on other frames - I wouldn't mind riding the RT-90 or EC-130-e frames for comparison!
With regards to my friends BMC Granfondo 01, his frame imploded on the flat. Top tube split across the middle - no crash involved. Under warranty, but neither Evans or BMC would honour it. Was offered a goodwill replacement for £700.
it's cheap because it's old/been around for ages, they've got newer frames around but many, pro carbons are still on the roads and I've heard no complaints from anyone about the frame. Yes it is not as stiff around BB as the top end cervelo will be but I have literally seen one review mention stiffness, everyone else is more than happy and upgrading from a cheap alu frame will make a massive difference.
