I've had good luck with any router except for the Airport Express.
I am currently using a Mikrotik RB951G-2HnD. I want to get an Ubiquity PicoStation M2-HP. These both have very high transmit power (1000mW). I like the form-factor of the PicoStation because it should be easy to mount on a stand to get it above peoples' heads.
It seems that if you reboot the Airport Express after the X32 has booted, all works fine (at least for me).
I use Airport Express too, but I have one issue. It "looks" for internet and mutes for a second every 30 seconds or so, I like to send audio thru it from the iPad, so that disrupts the music. Have you had that issue or do I have some setting wrong?