The first (and will probably be the last) Encore card I bought barely worked. I got mediocre speeds, lots of connections dropped, in both Linux and Windows. It was probably just a defective one, but sorry, not gonna risk getting another one. I've used two of these: http://www.newegg.com/Product/Produc...82E16833166021 and they work great in Linux and Windows. Only $14.99 too.
As mgc8 says, PCI rt2860 devices are not a great choice, as the Ralink driver is not well maintained. Particularly it uses the old wireless stack, which the kernel developers and userspace networking guys are very keen to get people away from. As as mgc8 says, there is a 'proper' driver but it's not workable yet.
I have a card like this. It works okay with rt2860sta, but even on an 802.11n network, not very fast - barely faster than g. (I notice your screenshot shows yours running at 802.11g speed, not 802.11n...) I'd much rather have one with a decent driver.
I mention these because they have an Atheros chipset. Atheros is well supported in Linux?
I am considering the two above but not sure I want to pay the extra for PCI-e although it's appealing because many motherboards only have 2 PCI slots. I might not need the PCI slot if I ever upgrade my sound card to a PCI-e sound card and right now, I'm not using the other PCI slot.
i've used 2 of these cards for over a year now and, while its true it works 'out of the box', that's only in g mode. trying to get it to run in 802.11n was a pain. i managed to do it under ubuntu 9.10, but since upgrading to 10.04, i haven't had any luck. i can get it to connect using n (270Mbs), but that connection rate rapidly drops below 54Mbs once the network is utilized. i've since removed the card and just connect by lan....