In the UK we do a lot of wrapped bales - big square, round and small conventional square bales for horses.
Silage is often baled and then wrapped when it is not worth having a clamp, eg for a small heard or for a last cut when opening up the clamp again is not worth it. Also, the wrapped bales are very convenient when you just need a bale somewhere, and you can transport them and sell them.
Wrapped round or big square is pretty much the same, but some of the big squares can weigh an absolute ton. Most of the rounds are kept to 4ish foot to make them easier to handle. We tried some 5ft ones before and the net broke when we tried to pick them up with a spike.
We also have a little bale wrapper for small squares, you have to man handle the bale on to it and then press a button and is wraps it.
They are mainly used for making haylage - basically slightly damp hay. It is helpful because you can bale a bit sooner, so the weather is not so dependent, and most horse owners say the hay is much much better.
It is completely dust free, has more 'goodness' apparently in it, and contains much more energy. You don't need to feed horses as much of the stuff.
They also command a massive price premium, probably the equivalent of $7 more per bale. And the best bit is that the bales are baled a lot shorter, so you get more bales per field. If you make them too long, the bales are too **** heavy to pick up, especially when you have no string to hold.
The wrap has got quite expensive, but they are still popular. If you would like some more details on them I will try and explain.
Some of the big round bales have a set of knives behind the pickup, so they can chop the grass before it gets baled. They use a lot of fuel when there chopping though, but a lot of farmers like them chopped still.
We have a separate wrapper so we can send the baler and wrapper to different places, and most of the wrapping is done at night. We take it in turns whos wrapping each night.
Wrapping is also the most mind numbingly boring job there possibly is during the summer, especially at night. And you have to get out of the cab every so many bales to change the rolls of wrap over which gets old quick.