aperture, aperture, aperture...
If you have around 2k to spend I would go with the biggest dob you can handle... I know you mentioned grab and go, and a dob really doesnt suit that so much... But neither does a megrez88 and a mount...
I started with an 8" dob earlier this year, and really miss the ease of use involved with it.. pick it up, put it outside. - Done..