Strictly in terms of reliability as you asked, the 7.5s are a pain in the ass. I've long since gotten over the "fun" of tinkering with a gun to make it run and prefer to have guns that shoot reliably and do so from the get go, with whatever additional tinkering I do being on a voluntary basis. If you have the time, like a challenge, or are just lucky the 7.5 may be feasible for you.