The MSI 850 Pro has a slightly odd layout. The most striking oddity is that the IDE and floppy connectors are rotated 90 degrees from the norm, near the end of the RIMM slots. This did not prove to be a problem for us, but it is worth noting.
Another oddity is that the supplementary 12V CPU power connector for the Pentium 4 processor is located right next to the primary ATX power connector on the top edge of the board next to the end of the RIMM slots. In addition to supplying extra power for the CPU, the 12V four-prong connector was intended to reduce power routing headaches by allowing the CPU power source to plug in next to the CPU, away from the other power connections. The only trouble we had with the power connectors is that, with the primary ATX connector installed, the clearance for putting memory in is a bit tight, but this is a minor nitpicky flaw.
The CPU socket has ample clearance around it, clear from capacitors, so mounting the heat sink is an easy task. We expect a more radical cooling apparatus would fit with little trouble.
The MSI 850 Pro is available with optional CT5880 Creative audio. Our test board, which lacked the Creative solution, came with Yamaha 4-channel audio integrated. Unless you plan on setting your PC up for home theater, the Yamaha audio will likely be sufficient. This Yamaha audio is also optional, and an audio-free board should be available as well.
The MSI 850 Pro comes with all the brackets necessary to attach a heat sink to the board. It does not, however, come with RDRAM continuity modules, which are necessary if you intend on filling only two of the four RIMM slots. If you do need to buy these "CRIMMs", a pair of them will cost you about $20. This is another point where ASUS' P4T outdoes the MSI 850 Pro, since the P4T does come with two CRIMMs. We expect most users to need two CRIMMs.
The MSI 850 Pro also comes with a plethora of small utilities to help your system run and overclock. The most interesting utilities are MSI Live BIOS, for easy BIOS updating, Trend PC-cillin 2000 for virus protection, EZLOGO for BIOS boot screen customization, FuzzyLogic for automatic overclocking utility, and SoftCooler, which runs a low intensity application thread to reduce CPU heat in case of overheating. We would have liked to have seen BIOS overclocking/tweaking options.