I have 2 E2500 Version 1 here and tried all three current Tomato versions - Shibby, Toastman and Advanced.
I had the 2.4GHz in client mode and 5GHz as AP. It is not usable, the 5GHz part fucks up every half hour or so and I need to unplug the routers. I can't see what's wrong - sometimes I can still access the HTML config but it doesn't show anything abnormal.
The failures can reach from no access to internet/WAN side to no access to router's HTML but still internet access to complete block of the 5GHz wifi - despite Windows still connecting to it. Android wouldn't connect any more in that case. Too bad, nice small device would have been ideal but absolutely unusable.
Any idea if an older version might work better and which? I read somewhere else that problems with the 5GHz band were present even in the original firmware and fixed in the 2.0.0 Linksys firmware. I also tried flashing that one and then Tomato again, but similar failures still occurred.