I use a Caroni 59" rear discharge behind our 3038e when mowing at the mother-in-law's place. I'm not sure about the "stripe" thing, since I haven't noticed that effect it probably doesn't.
The quality of the cut is at least as good as was done by the 48" deck riding mower used previously, and at higher travel speeds. This is most noticeable where the grass is thickest/longest. The PTO powered blades have the advantage. Where you'd have to cut twice or move at a crawl with a riding mower, the PTO finish mower handles it without a change in speed.
The down side to pulling a finish mower is in regards to trimming around things like plantings, trees or things with irregular outlines. The mower deck is positioned behind the rear wheel turn point, so it will not track on top of the inside tire's path when turning sharply the way a belly mower does. With a rear mower there would be a noticeable space between the inside tire track & the mower track for the duration of the turn.
The only way to offset that is doing some cutting in reverse, which puts the mower track to the inside of the tire track during a sharp turn. For straight lines, gentle turns, and open areas it is not an issue, just when you are running your tire right beside items. Things might be different with a mower wider than your tractor width, but that could add additional, different, navigation issues.
The other consideration is the potential for a rigid top link connection to limit the degree of "float" available to the mower when traversing a sharp hump or dip. This limitation could result in either the lead or trailing wheels being cantilevered off the ground enough for a patch of irregular cut length. This potential limitation can be reduced by using a more flexible top link connection - such as using a length of chain in the connection - if needed.
The only other thing that comes to mind is the form factor of tractor + mower. It is probably significantly taller than a riding mower, which might limit where you can go. Also, the combined length of tractor + mower (especially if you have a loader mounted) might limit those areas where you can turn around, or back into.
Having said that, it is still the fastest way to cut her yard. We used to spend 6 - 8 hours (depending on grass height) mowing using a riding mower with a 48" deck. The 59" Caroni behind the 3038e gets it done in 2 - 3 hours, which is quicker than the times when we would use 2 riding mowers simultaneously. Even with the trimming hassles.
Nick