The reason why some folks prefer prison over the county is amenities. In most county jails, you don't get rec. There's no GED program. There's nothing. You literally in that bytch sick ... just stuck. Facilities are terrible. Plumbing fukked up. Usually no on site medical professionals (mental/physical health). And that's usually because it's funded by the county, and it's not viewed as a priority...the county jails are really just a holding area until the disposition of your case. Whereas the state pumps big doe into the prisons, and there are much longer stays, so it's much more shyt to do and you get the best medical care.
With that said, it's a trade off if you had the opportunity to do your time in prison (occasionally on short sentences, if the jail is overcrowded, you'll get shipped to a nearby prison to do time), although there might be more to do, the inmates are usually more hardened. A lot of it also depends on whether you're in a minimum or max security prison.
However, don't sleep on county jails, especially those in bigger cities... LA County, NYC (Rikers), New Orleans, ATL, Essex County, etc. A fair chance of getting the top knocked off...