I have owned a set of metric and SAE and used them professionally every day for over 10 years. I have long thought that this style ratchet wrench is some of the best money I've ever spent on any tool because of it's convenience. I have broken 1 and had another that the ratchet mech was a little hokey from the beginning so both were easily replaced. The biggest downside that I can tell you is this - the open end of them SPREADS easily when you put it on anything besides a loose bolt. This spread means that when I need a standard open end I have to reach for my old set to avoid rounding nuts/bolts. I can also tell you that the ratcheting head is bigger than a standard wrench (no surprise) so you'll still need regular wrenches for tight clearance areas.
If I knew for sure there was a better option that didn't cost an arm and a leg, I'd sell these and buy those. Until then, they're easily my most used tool. I just bought a set of Husky SAE & metric ratchet wrenches for my dad as a Xmas gift, but I didn't get to use them myself so I can't comment on the quality. I snagged them at a salvage place, brand new in the package for $25/set so I figured it was worth the risk. If I can get my hands on them I'll post back.