Not sure what sort of unpleasant experiences your friends have had. I seek out CRP grass to hunt. Lucas is a little different and may have other kinds of productive cover, but the parts of the state I hunt have little other cover available. The pastures are grazed too heavy for pheasants (although there can be quail); the wheat stubble is too short and sprayed with roundup too thoroughly; even the milo stubble seems to be pretty short these days.
Tough walking? always a little, sometimes a lot.
No birds? Sometimes, but I find a lot more pheasants in CRP than in other kinds of cover.
Crowded? WIHA areas can be, especially early in the season. Mid January you won't have any trouble finding one that you don't have to share.
Tough to find downed birds (especially quail)? Yes, but good dogs help a lot.
Hayed or grazed? Occasionally. I'm not an expert, but I think some contracts allow it on a reduced basis. Other times when there's a drought the authorities allow "emergency" haying or grazing.