This past Sat I heard on local radio station call in program about anything automotive/off road etc where a caller asked about the Triton V-10 in a Class A and the host more/less shot the engine down....
The spark plug issue is long gone. Any used rig you find either never had the issue or it's been fixed.
RPM doesn't appear to be much of a factor in lifespan. It's common to see them with 200-250k miles (currently at 210k on our F250). I've heard of a number at 300-500k miles without a rebuild. Also cruising at 1800-2000rpm isn't anything to get excited over.