I feel your pain re: trouble running emulators for dev work. We built Manymo to address this pain. While it does not (yet) emulate custom android builds, like the dreaded HTC Sense builds, it does give me an emulator faster than I can spin one up locally.
I typcially develop with a phone and a tablet but using Manymo I can spin up a larger tablet or an odd-sized phone emulator to check how my Fragment code is laying out on a variety of device configurations. All of that without soaking up memory on my laptop. It helps testing against OS versions too. We also find it extrememly helpful when working with designers that do not have the SDK setup. The list goes on but suffice to say we are excited to see more people use this tool.