If I may have the soapbox for a moment... Here are some facts, please take them with a grain of salt.
The motherboard is a fairly standard micro-atx design (save for the backplate, which a replacement for most pc-backplates is included). Even some of the larger towers support this design. The screw-holes match up with any case that supports micro-atx.
The memory is picky. If you consider this solution, do your homework on memory before purchasing any dimms. I cannot emphasize this enough. I had no trouble, but I did my homework first. There are horror stories around about using the wrong memory, so this is where you must be careful.
Use UDMA cables, they allow for better data-transfer (btw, this also applies to amithlon setups). Remember disk-access affects anything that reads/writes a cache.
General perfomance: It's faster than my Amithlon ( 950MHZ ). No if's, and's, or but's... this thing is FAST. It makes Win2k on the same 950MHZ peecee (as amithlon) look like a Timex Sinclaire trying to run Quake.
Compatability: You're going to find mixed answers for this. I've got a compatability FAQ on MorphZone, with links to some other compatability links as well. The biggest thing that doesn't work, that I would like to work, is AmiDock. However, if you run Magellen or NetConnect's dock--you will hardly miss it.
To get back to my original point: do your homework. Whether you are building for MOS, OS4, Amithlon, or a PeeCee--do your homework. If you spend the time up front to check with others about what hardware works, and what does not, you will save yourself all kinds of headaches.