Benchmarks:
I built two systems, the BXMaster system and the comparison system, my old BX6r2. I used all the same components, putting the second system together after finishing benchmarking the first, deltree'ing and reinstalling Windows 98 and 2000.

Mainboards:
MSI BXMaster
Abit BX6r2

Same components used in each system:
Pentium III 500E
Aopen TNT2 Ultra (standard clock speed)
Accton PCI 10/100 NIC
Creative AWE64 Sound Blaster
Seagate 6.4Mb drive, ATA33
64Mb CAS3 PC100 AOpen SDRAM
27Gb IBM DPTA 7200rpm ATA66 hard disk drive (MSI board only, for ATA66 benchmark)

The original setup used a KingMax PC133 128Mb DIMM, but I switched back to some PC100 because of the previously-described powerup problems (I didn't work out the 400W PSU fix until after running all the benchmarks!) The reason why I didn't choose a more comparable DIMM in size and speed to the KingMax was because the AOpen was the only other DIMM I had available. The RAM test results will be relatively low, but at least you will be able to see the comparison, any newer and more compatible RAM will certainly get a higher Sandra memory benchmark score.

On both boards I used the setup defaults. I used SiSoft Sandra 2000 under Windows 2000 for 3 speed tests, CPU, CPU Multimedia, and Memory. I ran them all 8 times each at 550MHz, and 8 times again at 682MHz (124MHz bus, 31MHz PCI). I kept the highest reading of each of the 8, which I found was always attained within 5 runs. Memory benchmarks tended to fall away after the initial test, so I made sure I did a clean boot after power off and ran it as the first thing. Since I don't really like or trust benchmarking programs, I also included a real-world benchmark, Quake3test, run under Windows 98.

Sandra CPU and MultiMedia Benchmarks:

You can see the difference between the two boards is negligible.

The memory benchmark shows the MSI being slightly quicker than the venerable Abit board. How does this translate to real-world performance? Quake3 demo1 shows us:

I could not run the Fast or Fastest benchmarks, for some reason they would shut down my Hyundai monitor. It happened with both boards, so it was probably a software issue (or just my monitor crapping out at low res's). The MSI shows itself to be slightly faster in the Normal timedemo, at High Quality both motherboards unfortunately run smack into the fillrate limit of my TNT2U video card..

I did not bother with the Sandra hard drive benchmark, in my opinion it is totally inaccurate and does not reflect real-life situations at all. Using HD Tach I got a maximum thruput of 23529kps, which was virtually the same as on my KA7. The big difference though is in CPU usage, the BXMaster getting 3.5% usage, and the KA7 41.8%. I assume this is to with the BXMaster's PDC 20262 chip taking a load off the CPU in a way that the KA7's KX133 chipset doesn't.

Overclocking with the BX chipset is always interesting. My TNT2U card isn't particularly tolerant of high AGP speeds and with BX that is always going to be an issue because of the lack of a 1/2 AGP/FSB divisor. I found the motherboard to be stable at 140MHz FSB, but it wouldn't run any AGP stuff. 150 was pretty much a no-goer, got to the login screen in Win2k and froze. If you chose your video card carefully or used PCI, I'd say you'd be able to run this board stable at 140+ FSB.

Conclusions:
To sum up, this board seems to be quite good and stable, but it is not without its annoying quirks. The really major one that I experienced is the possible sensitivity to RAM or PSU. There are the usual limitations of the BX chipset (no 1/2 AGP setting, for example) but you get the memory speed that the good old BX chipset provides. It is definitely fully featured and if you require the extra bus mastering slots that your current board doesn't (as many of us do) then it's a worthy upgrade from an older BX board.

Pros:
6 bus master PCI slots
ISA slot
4 DIMM slots
8 IDE channels
Board potentially hackable into RAID interface
Good amount of overclocking options including voltage
Plenty of space for a big heat sink
D-LED diagnostic tool
ATX power control after power loss
Metal clip on thermal probe
Onboard speaker

Cons:
Possible RAM / PSU sensitivity
Outdated BIOS interface
BX limitations (No 1/2 AGP ratio, no +33MHz memory)