I had a chance to ride one for two weeks. I tested the Cervelo S3, R3, and a Tarmac in the same week. I unfortunately was not too fond of the BH. The front end felt stiff and very responsive but the rear end felt mushy and not tracking correctly with the front end of the bike. I felt the bike was smaller in some sort of qualitative manner and felt jumpier. I spent some time descending on very long and steep hills and I wasn't very confident in it's handling coming down the mountain at 50mph. Aesthetically I think the bike is gorgeous but there is something fundamentally odd about the frame, I tried compensating for the shorter head tube via fit and I tried various wheel sets along the way. So in the end I think the consumers money would be best spent on another bike. The only long non-biased review I could find on the web was here:http://www.epictrain.com/Product_BH_G4.html
and although the review was on the g4 I felt the exact way about his comments on unstable out of saddle efforts.
Where exactly did you get a chance to spend two weeks on a G5? I am a BH dealer so I admit that I am biased, but you posted this on the 21st and the first G5's to hit the states for resale got here on the 15th. The only models in the states before that were demo models that magazines got to review , and so far, those reviewers have responded favorably, and one refuses to return the bike. You must be quite privileged to get to ride this bike and those other high end bikes before anyone aside from some designated press do.
I ride a G4 and like many others I found its fault in front end stiffness (lacking), rough at times, and very quick handling but the positives of the bike (flat out fast) more than made up for those shortcomings. I got a G5 in as soon as I could (Monday) and This bike is amazing. It takes the faults of the G4 and makes up for them in spade. I confidently sprinted in and out of corners, and felt very secure on the bike.
I have ridden tons of high end carbon, ti, and various material frames and the G4 ranks among the top 10 and the G5 is vying for first
Also, "shorter head tube"? what size are you riding? I ride a 57 G4 which has a fairly tall head tube at 175mm, and the G5 is 185 in a 57cm. Tell us the size you tested, and the size of the other bikes and the height of their head tubes. Also, you reference an online post about the G4, is the review you posted for the G4 or the G5? Because they are significantly different bikes.
PS- the photos just posted above are from my shop and I am thrilled to see them popping up elsewhere on the internet. the top two my brother took (he is becoming an amazing photographer) and the third is mine. Glad you found the pics!