I too am looking to build an Athlon64 system, and after doing days of web research on which mobo I should start with, I came across the MSI board in question. You have some of the same questions that I had, so let me help:
- I just saw this morning that zipzoomfly.com is taking orders for the board, and they are the first to my knowledge to offer it this side of the Atlantic, for a good price, too: $149.00. Check it here: <A HREF="http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=241132" target="_new">http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=241132</A>
- MSI is a very reputable brand. Since you're looking at A64 boards, check out their other A64 offerings, like the K8T Neo FIS. Debatedly one of the best K8T800 boards out there. Keep in mind that the big hurrah about the Neo Platinum board is not only its great performance, but its great performance as one of the first implementations of the new nForce3-250Gb chipset (-set). VIA ruled the first release of A64 boards with the K8T800, as the nForce3-150 had some serious issues. So, Nvidia's hard work has shown, and it's now on par with the K8T800, and in some cases superior. Assuming I can link directly to the article, THG has a great look at the new nForce3-250 at <A HREF="http://www6.tomshardware.com/motherboard/20040420/index.html" target="_new">http://www6.tomshardware.com/motherboard/20040420/index.html</A>. As far as buggy BIOS and the sort, MSI's rarely ship with a bad BIOS revision, and even if they do, MSI seems to be fairly quick with web-accessible updates.
-Cool & Quiet is supported on the board, enabled/disable through the BIOS, though it is debated if C&Q is even all that useful.
- Nvidia's hardware firewall is also described in that same article. Nice feature, seems to just add security instead of replacing a better firewall solution.
- Nvidia's claim of gigabit LAN does simplify things and show signs of increased performance with a shorter signal path, instead of sitting at the end of the PCI bus and limiting the bandwith requirement for a full-duplex gig connection. This is also looked at in THG's review. Chaintech's solution uses the nForce3-250 non-Gb, so if they were to add gig LAN, it would most likely sit at the end of the PCI bus like most other boards. This isn't necessarily bad, but if you want maximum bandwidth all of the time operating in synch, 250 Gb seems to be the way to go. Whether or not a home-user will ever take full advantage of a gig connection as much as would qualify for this performance increase remains to be seen, i.e. it's probably not "to-die-for technology."
- As far as the rest of your post, look at THG's article I linked above, and take a look at the rest of the new nForce3-250 boards, as well as the VIA K8T800 boards. I'm choosing this board for a few reasons: features, design, manufacturer history and quality, and overall hardware review sites that I trust, like Tom's. Good luck with your search, and may the best board get your adoration!