Define Choss...vs Cleaning Up

What defines choss for you, I mean really crap rock/don't waste your time to bolt rock?

For the past year I've been climbing at the Red, and I've heard/seen a few of the developers of a newer crag state that their area has "some of the best rock/lines" in the Red. But with the caveat that it's still "cleaning up". I have a novice understanding that sandstone cleans up differently than other rock types (I've climbed on granite and quartzite before moving to the Red), but if every time I get on a route I'm popping footholds off or finger jugs are flaking, I'm starting to think this particular crag is a mossy, chossy hole.

By comparison my previous home crag was a tiny granite choss-pile, but in probably 200 burns there I broke one hand hold. Within the Red itself, so far, I've never had anything break at a place like PMRP. At this newer place, I literally have some rock break on every route.

Sounds like the rock at that new crag could just be soft. If that’s the case, “cleaning up” could mean that the rock breaks until all that’s left are rounded slopers, slimpers, and only the largest of features

It's all relative, and it can be hard to tell what something will be like after it cleans up in 5, 10, or 15 years depending on how much traffic it gets. Or if it's really chossy then it will never clean up with any amount of traffic. But "some of the best lines in the red" is probably more than a little bit of a hyperbole because the bar is supposed to be set pretty high there.

Around here, lots of the crags that were being developed in the 80s and 90s were called choss piles at the time and today they are a sport climbing paradise for durangutangs 

Matt Clay wrote: What defines choss for you, I mean really crap rock/don't waste your time to bolt rock?

Sometimes the choss is where the good climbing is.  In my experience the epic looking clean faces are often just too epic-ly hard to actually climb. Where as a nice wall with chossy looking rock usually has a lot more holds to work with. 
At the end of the day, It depends on the stoke level of the developer and the size of the bolts they have access to. I’ve personally met very lititle choss that meets your definition but my stoke level is high. Developers walked right by peices of Rock where I later put up quality-ish routes.  In the end, the FA always has more stoke and sees more quality in a route than the next 20 climbers. It’s harder for non-FA folks to walk up to an existing route on soft rock and separate good movement from just calling it all choss. The FA has cleaned every inch of the route and knows all the moves before their belayer ever sais “On Belay”.