The main difference between the two shotguns is the bore diameter. The 835 is overbored to almost 10ga bore and the 535 is standard 12ga. This means the 835 is good for patterning large payloads of pellets, but not the best for small payloads. Mossberg also says NOT TO SHOOT SLUGS in the 835 unless there is a specific slug barrel being used.
I for one have little long run faith in either, but know friends that like them. The standard 870 is still my go to in a pump gun.
