I used an Express in ProxySTA mode connected to a 5 port switch for my home office config. The ProxySTA mode is not a network extension in the traditional sense, but runs as a wireless client that converts the wireless back into a wired network. I did have issues with occasional lockups on the Express. This would typically happen once or twice a month. I got in the habit of resetting it once a week to avoid issues. I also had lots of problems with the el-cheap-o switches I used. I tried several of them, but all of them had to be power cycled periodically. The outbound (PC/Mac->switch->Express->rest of the network) would work fine, but other systems in my house would be unable to reach an HP laser printer that was hanging off one of the ports on the switch and I would have to power cycle the switch to get it accessible again. I have recently switched out the Express/switch combination in favor of a 1TB Time Capsule extending my 5Ghz "N" network. I have been using this config for a month and have yet to have an issue. I am hopeful that Apple has worked out the 18 month power supply issues with the TC.