If you can carry it then it's useful ...
HantsAstro is doing something that a lot of astronomers in the area thought couldn't work: locating dark skies sites in the South of England that are good enough and consistent enough for deep sky observation and astrophotography. There is a caveat: you have to carry the stuff.
While 20" Dobsonians are nice (read fabulous with a big F!) to look through, they are somewhat, er, large.
HantsAstro offers reviews of some of the best kit that's out there, and how it fares on a long term basis. It's often said that the best telescope is the one you use the most.
Our current test fleet ranges from 70mm (3") to 200mm (8") diameter. From small sweet, fast Apochromatic refractors, funky little Maksutov-Cassegrains through to old school Newtonian reflectors.
Pretty much anything up to 200mm (8") is easily portable, up to 300mm (12") if it's a Dobsonian and you're feeling a bit fit. It all depends on how much you wish to spend, and what kind of astronomy you want to do.
There is also the other stuff. Mounts, tripods and clothing. Yep, clothes - standing still outside at night is not good, so you will need to adopt a multi-layering system of dressing and a warm flask of coffee at hand is even better.
And with new friends it's best of all. Now we are finding new ones. Hello.