I haven't seen the H25 but I doubt it can be as small as the Joey. The Joey is pretty darn small.
that's why i got both hoppers today. We could have made due with one hopper with some careful management or not worry about managing anything and cough up the $100 for a second hopper.With another round of upgrade fees, of course.
If lack of tuners is an issue then get a second Hopper. The only challenge at the moment with that is getting Dish to activate 2 Hoppers with only 1 Joey.