A couple of other points of interest.
- Both the DMK and the LPI (to a lesser degree) can be used to image deepsky objects if you have tracking and can make use of the longer exposures available (60 min for the DMK and 15 or 16 sec for the LPI).
- The DBK comes in colour as well so you can get the best of both world of fast frame rate and colour so you don't have to muck around with filters (which bring additional cost in filters and filter wheel.
- I belive the new DBK style cameras now come in USB 2.0. I doubt if the frame rates will ever match the firewire version, but at least it is plug and play if you don't already have 6 pin firewire on you laptop.
From a purely personal perspective, I couldn't wait to get away from the LPI, I found the ToUcam far easier to use and produced a more pleasing result...but I will admit I didn't persevere with the LPI for very long.
btw I'm wrapped in my mono firewire DMK. It is a great little camera. Very versatile