As a new Power Macintosh 7200/90 owner, I wanted to pass on a few impressions and a warning. First the warning: Beware the kickstand! After opening the hinged power supply and drive assembly (which works great!), I installed extra DRAM and VRAM. I then moved to close it - there was a moment of slight resistance, then SNAP! I had broken the little plastic kickstand that is meant to hold the machine's swing-out assembly upright. It took so little effort to snap that it doesn't seem capable of providing much support. I then read with amusement three reports in <comp.sys.mac.hardware.misc> from people who did the same thing. One of them reported that after suffering on hold at 800/SOS-APPL, Apple sent them five new ones in the mail. Owners of the 7200 and 7500 should be careful of this little kickstand.
In terms of memory, I found out some interesting facts. My Apple dealer and also a RAM vendor were under the mistaken impression that the 7200 does memory interleaving. It doesn't, although the 7500, 8500, and 9500 do when DIMMs are installed in pairs and in paired slots. This means that it's better for 7200 owners to get one 16 MB DIMM and save some money and a slot, rather than buying two 8 MB DIMMs.
Finally, neither the 7200 nor the 7500 ship with a level 2 (L-2) cache DIMM installed, so price or performance comparisons with the 8500 (which has a 256K L-2 cache DIMM) should take this into account. Also, the L-2 cache DIMM used by the PCI Power Macs seems to be difficult to find at the moment. Rumor has it that the L-2 cache DIMMs are constrained by supplies of the high-speed memory chips used.
[A quick check of memory vendors indicates L-2 cache DIMMs are more widely available, but many vendors were currently out of stock. -Geoff]