Summary: Out of the box, the system only supports 1 3.5" device internally. It does allow for two brackets that hold 2 2.5" devices each, allowing for up to 4 internal devices. But these brackets are not included (search for part number MCP-220-00044-0N if you need them). You'd think that for a server, even a small one, at least 2 drives would be used and Supermicro would include a bracket by default.
Pros: 1U, light weight, very quiet, IPMI, dual network ports, RAID support on the motherboard.
Cons: Only 2 USB ports. There are connectors for more on the motherboard, but even adding a PCI bracket with more ports is tricky due to space constraints. I would love to see Supermicro dump the two PS/2 keyboard/mouse ports and replace them with at least two more USB ports.
Summary: 1.1a is simply buggy from what I can tell. 2.0 resolves a number of issues. Not sure why Supermicro doesn't have this documented. I had to figure this out on my own even though I reached out to them for support. Perhaps my e-mail to them will force them to document this issue (as it's extremely frustrating not having a usable PCI-e interface with ESXi).
Pros: Supermicro tends to be decent quality. Haven't spent a ton of time on this server but it seems up to par with their other models. Good price for what it offers.
Cons: If your server ships with BIOS 1.1a, don't bother wasting any time to flash it to 2.0. ESXi 5.0 wouldn't recognize the Intel card (Intel E1G44HT) I installed (which is confirmed compatible with ESXi 5.0). Once I flashed the BIOS to 2.0, everything worked great.
Pros: we use these as our Tier 2 firewalls and SSL VPNs, as well as our Tier 1 VMware boxes. superfast and stable when combined with Xeon E3-1240 cpu and name brand ECC unbuffered ram and a good SLC SSD.
Summary: It has better cooling that similar Supermicro servers, but with a pure heat sink for the processor and only part of a single fan blowing on the CPU (no shroud), I would suggest a slight mod to add some additional fans.
Pros: Server seems to have a viable niche in the small footprint, high processing power (better than atom) with support for virtualization (due to processors), and a ton of other features.
Cons: Limited processor support. Currently Intel only has two processors in production that are compatiable with this unit; the E3-1260L (45w/4core/8threads) and E3-1220L (20w/2core/4threads) models. Neither of these are readily available, as they just came to the market 2Q/11.