I used a JD272 side discharge for several years. got a Landpride FDR-84 rear discharge last year. If you want to manage the clippings (pick up, etc), the windrow from the side discharge is handy. Otherwise, I really prefer the r-d. It spreads the clippings enough that they don't clump and suffocate the grass.
You can mow in any pattern, whereas with the s-d, you generally have to mow counterclockwise from outside-in, due to the exit chute being on the right. This is to throw the clippings over the previously cut areas. If you throw the clippings onto uncut grass, the mower will get really clogged and does a poor cutting job (if grass is wet, fuggetaboutit). And eventually you'll create some monster piles.
The r-d is simply more flexible to use.
One point about machine dimensions - a s-d's chute adds several inches to the width, whereas a r-d is only 2-3" wider than the cutting width, so if you store in a narrow space (barn, etc), you need to factor in that.
On the other hand, my r-d LP's deck is longer, which requires more room in the shed to store.
Before you buy, scrutinize the way the deck floats on the wheels. Any unit will cut decently on flat tabletops, but for uneven ground, several have wheel positions that cause the deck to scuff the surface, digging up, gouging the grass. Absolutely need the optional roller in the front too.
Hope some of this helps. jim
