I'll chime in here. All of my imaging is with a DSLR (i have a 1000D and a 400D). I don't have a permanent setup and have to setup prior to each session. I have two setups: a VC200L at f6.4 (FL 1278mm) on a EQ6, and a 130mm f5 newt (FL 650mm) on a HEQ5. All of my finished images to date have been with a guidescope, although I have recently purchased a Lacerta OAG to be used with my 1000D on the VC200L (although I don't have any complete projects with the OAG yet).
As my DSLRs do not have cooling, thermal noise is significant and will vary with sub length as well as ambient temperature. I have done a number of tests as per Roger Clark's methods
here to determine the required sub length to optimise SNR. For example, see my image of NGC6744 here:
http://www.iceinspace.com.au/forum/s...d.php?t=108354
So that takes care of sub length. I terms of total exposure, given that I am already behind the QE 8-ball by using a DSLR my strategy is basically to take as many subs as I can, however beyond about 200 and my PC is working pretty hard to integrate all the calibrated subs. So given that I typically use 3-4min subs during winter, that gives a total exposure of up to 10-14ish hours.