The IBM zPro isn't at the same level as the Ultra 40 M2, but then, it's not in the same price class as the Ultra 40 M2. It doesn't have the same aesthetic appeal of the Ultra 40, and it really looks like a small AS/400, but in a way, that's not a bad thing. It certainly looks powerful. And in reality, it is. The two dual-core Xeons aren't Opteron 2218s, but they're no slouch, and the same goes for the Quadro 3500. Internal storage is provided by up to four SATA or SAS drives with an optional RAID controller. The audio is pedestrian but functional, and the overall package is nicely appointed for the price, around $8k in my tested configuration. Like the Ultra 40, Vista Ultimate has no problem on this system, nor does FC5, 6, 7, and RHWS 4. With twin 21" LCD panels fired up and an installation of FC7, it's ready for anything.
Unless you're trying to find the last digit of pi, either of these workstations will knock your socks off and leave you wondering how you ever used a computer before. As I gaze at my dual 1Ghz PIII workstation from several years ago (which was the bee's knees then), the march of technology snaps into clear focus. The PIII is a doorstop now, not even really fit for server duty. These two workstations, however, have a long way to go before being relegated to inevitable obsolescence.
As I continue to work with these systems, I'll continue to post tidbits about them. If you're wondering, the forcedeth issue I noted awhile ago was from an install on the Ultra 40. Such is life.