Bought a German one (begins with L but name escapes me at the moment and my shed is currently 17 miles away), about 20 years ago. Currently out of action for reasons I'll not bore you with and it may be terminal.

I'd treat with scepticism any claims about how thick the machines can handle. Ours is a twin bladded chopper and will/would cope with up to 4.5cm branches, provided they were fed in carefully. But that doesn't mean I can feed a 2cm branch in with impunity. I found you have to learn the thickness of wood the machine can handle, or if not thick, the density of the material going into the feeder. Also some wood chops better when freshly cut, whilst other chops better when dry, so sometimes you can't get a clearing/cutting job completed at the time you are working.
Jamming on my machine is easy enough to rectify, (the feeder was held on by four readily accessible bolts), but if it keeps happening it becomes a PITA. So if you go down the shredder route, I'd check what you need to do to clear jams, before buying.
As to the blades, mine is still has the original blades. The blades are user replaceable and can be sharpened at home. Replacing the whole of the disc on which the blades are fitted would be likely to be a lot more expensive, so I'd check for that.
Oh and if you decide on one, get yourself some ear defenders.and safety specs. The machine might hum away reasonably quietly when turned on, but the noise, (certainly of mine) when shredding, gets very loud and bits can fly out of the feeder.