These scopes are tools, find what you can tolerate and use it. For myself I have found the C5 does what I need. It is the same weight as the C90, about as long, cools faster, has more light gathering/resolution than all the above scopes, utilizes the same focal length, has a ~26mm rear baffle vs ~16mm rear baffle in the C90, can fit the brighter Pleiades in the same FOV, and is extremely portable. For me it is the "something for nothing scope". Decide what you like, get it, use it, love the sky!
I agree about the C5. It comes closest to a master-of-all-trades light-weight grab-n-go scope. It cannot match the wide-field low-power views of a C80ED, but when fitted with a 2" diagonal and 2" eyepieces, it surpasses the C90 in TFOV. And it betters both C90 and C80ED in light grasp. The C5 also has greater resolving power than the C90, and also the C80ED, at least theoretically. But the C80ED has better contrast and cools quicker than the C5. So overall, I would tend to use the C80ED for planet/lunar/doubles, at least during the colder months, and the C5 more for DSO, except the much larger ones, where the C80ED would show an advantage.