I have a 18hp craftsman something 2000. I got the extended warranty on it but its doing well. I've had it for 2 years. Nice mower. Briggs&stratton engine gives me no problems. Manual tranny since switching gears is so easy on need to spring for automatic(step on pedal, pull lever to gear, let up on pedal). The only problem I've had with it is its got some arms on the front frame to the deck. The right front arm keeps falling off and twisting. II thionk its because I have to mow around a lot of raised mulch thattwists and throws it off. Covered repairs under the extended warranty though ans I've learned to drive it better so I dont do it anymore.
Craftsman is godo stuff usuallly. I got 1 gas blower/vac, 1 electric blower, 1 push mower, 1 lawn tractor, a bunch of tools and tool boxes that are craftsman and they work well and in the case of when tools invaribaly break(even impact sockets will break with a few hundred pounds of torque), i get them replaced no questions asked.
btw, i;'ve got 1.5 acres and it takes me about 45 minutes to maw the 2/3 of an acre or so covered by grass.