Yea, they work great, thats what I use. They don't map trace, but thats not a big deal most of the time. These make tuning new injector types a snap.
Like Nate said, you need two and you have to wire the serial ports together (not hard, just Y the serial line (TX and RX) from the computer to both romulators (they share a single serial connection)). I can post a schematic of it for you with digikey part numbers, or send me the romulators+an ecu and I can build it for you. Its not hard, but its easier to just build a dedicated ecu for this than swapping the romulators in and out.
This is mine (older pic, now moved to a daughterboard with consult bundled on board), boxes on the romulators removed and the pcbs mounted to the top of the ecu (the lid is a spare ecu bottom, giving access for the cables to run inside the lid). What you can't see is the serial outs of each romulator are wired together just below the bottom of the picture in a single serial shell.
Btw, I host the romeditor site. Lawerence is a cool guy, and the rom emulator he works with (the expensive one, $1200, wish I had one) is a very cool toy. Cool stuff, but I don't use the software. I pretty much just use rom editor (old stand-by) with a little program I wrote for working with the romulators. If you end up going with this setup I'll post the program.
