My first mechanical keyboard was a Razer Blackwidow with Cherry MX Blue switches. Next, I bought a blank-key Das with Cherry MX Brown. Since then I've used an Input Club K-Type, a Tesoro Durandal, and some Logitech keyboard with MX Reds. I actually really liked the MX Reds, way more than I thought I would. So when I ordered the Ultimate Hacking Keyboard it was with Box Reds. I also still have an Input Club Nightfox waiting to be assembled in my closet - it's been there for years. I should probably just sell it at this point.
In regards to layouts, I too prefer US layout for coding. But I live in a European country with special characters and have gotten used to using that layout. The UHK, however, will come with a US layout and I'll map the special characters to alternative keys. I hadn't delved much into special key mappings on my boards yet, so that'll be interesting. I got it with the trackball module in hopes of never needing to use a mouse again.