I got a Merida 904 with 105 (Tiagra chainset) last October and it rides really well. The rear hangar snapped, miles from anywhere, 2 weeks ago but this was due to debris getting blown into the rear mech while climbing - don't know if this is a sign of some weakness or not. It's light and responsive, or at least it is compared to my previous steed.
The Merida Road Race 903 with Tiagra throughout got a 9/10 review in Cycling Weekly back in 04/02/10 issue. Picking out a few quotes:- "Geometry is racing...head tube is shorter...it's also oval-profiled for extra stiffness...The frame's graphics are possibly a little unsubtle...feels lively, solid and steers well...It's one of the best, if not the best that we've ridden at this price point."
Hope some of this helps.