I have had a bagger system on 2 different mowers, both 2-bag and both soft. One was a 38-in. deck MTD (Wards) tractor mower and the present one is a 48-in. John Deere ZTR with blower system. I like the soft bags because they allow free flow of air through the mesh bags and I think that provides better flow of the grass into the bags. They collapse and therefore require less storage space when removed. Also, the bags are easily replaceable on the top steel support tube ring and are fairly inexpensive. The bags on my ZTR are much larger than the tractor was, and many times I don't have to stop midway to empty them for my 1/2 acre lawn like I did with the tractor. However, when they are full of moist grass they are heavy and a pain to carry any substantial distance when dumping.

The plastic bins are no doubt durable but you may have to replace the whole bin if damaged. Don't know about their weight. If they are designed properly, all of the bags on the 3-bag system should fill OK, but without a blower system as on my ZTR there could be a problem filling that last bag with moist/damp grass without clogging the discharge tube first.

For side discharge, the tube is easily removed and the bagger can remain fully assembled on the back of the tractor..... at least that was the case with my two systems