There’s not a great deal to say about these cards apart from that they allow you some crazy network speeds, if you have the disk speed to keep up. They can certainly alleviate network bottlenecks if gigabit is holding you back!
This particular card has a fan to keep the chipset cool; it’s not going to be heard in a server room but if your workstation is quiet the high-pitched whine is probably going to be audible.
The card does get reasonably hot, particularly if you’re making good use of it’s capabilities – make sure you have enough airflow in the chassis to keep the card cool. Keep in mind it’s assumed that these cards will be used in an environment where there’s at least 200 linear feet per minute of airflow passing over them.
10-gigabit cards are coming down in price quite significantly, though switches are still out of reach of most enthusiasts/small businesses. Watch this space, however, as 10GBe connections are making their way into high-end server boards more regularly and that will slowly filter down to the consumer level. SSD arrays becoming more commonplace will only help with that, as will the new 12gb/s cards from LSI – it’s hard to make use of all that bandwidth if you’re piping it over gigabit!