In case I didn't mention it, the E3000 is simultaneous dual band, meaning you can use the 2.4GHz and 5GHz radios at the same time so can support 802.11G, 802.11N 2.4GHz and 5GHz and yes, 802.11a 5GHz (but who uses that any more hah) all at the same time. Some routers only allow one or the other.
I like Ubuntu very much. You can run OpenVPN on your Ubuntu box or if you get an E3000 you could use a 3rd party firmware that includes OpenVPN.
I like/run
Tomato, has a nice set of
features including a QOS generally considered to be very good and better than the QOS in DD-WRT. There are quite a few
quite a number of versions of the Tomato firmware. I like/run
Toastman builds. Checking my E3000, version I'm running now is shown as the "Tomato Firmware v1.28.7495 MIPSR2-Toastman-RT K26 USB VPN" build. Looks like it's up to v1.28.7498 now but I usually don't worry about keeping up with every release unless I'm having problems.
If you do decide to load a 3rd party firmware, make sure you're comfortable with the process before loading it. For Toastman, read the text files in the repository at 4shared.com. Note that you might have to set up a free account there now to download the files. Didn't have to in the old days but since the DMCA crackdowns, shared files aren't allowed on most such sites any more.
Also head over to the
Linksysinfo and/or the
TomatoUSB forums & ask any questions you have.
I love Tomato firmware and have run it for many years. But it's not for everyone. I never run the stock Cisco/Linksys firmware and always load up Tomato immediately when I get a router. And of course I only buy routers confirmed to be supported by Tomato. Actually I did buy a couple which wouldn't, one that was on sale and later regretted that. Another was a travel sized router which I wanted but Tomato would not run on it but I did get DD-WRT on that one. So I really can't comment a lot on the stock firmware but it's probably quite adequate for most purposes.