I've had one for close to 30 years and it's never failed on me. The aluminum receiver will never rust and makes for a lighter, easier carrying gun. I have found no balance or swing problems with it. The rotary bolt is incredibly smooth and fast, and locks into the barrel extension. The other working guts of the 1300 is similar to the 870 - stamped carrier, twin action bars, stamped parts in the trigger group, etc. I've never seen the problems in my gun that I've seen in a couple of 870s in the field. One of the single biggest differences between the two is the chokes. The Winchester choke can be removed by hand as the knurled edge extends past the barrel (thus also protecting the edge of the barrel). The Remington choke fits flush with the barrel so you must use a tool to remove it. Also, if you ding the edge of the 870 barrel, you also ding the choke and it'll be a b!tch to get the choke out.
Yeah, I have those wear lines on my receiver from the foreend, but it doesn't bother me in the least. I've seen too many rusty and pitted 870 receivers to offset that.
Grouse Man