Remington 1100 Magnum was my first gun... I would recommend them to anyone.
As long as you keep the O-ring clean, and in good condition, they run flawless.
Also, you might want to note that if you DO come across an older 1100 Magnum (3" chamber), they are designed to cycle with 3" shells only, not 2 3/4". I found that 2 3/4 hunting rounds did not cycle the action reliably.
The older 3" chamber barrels only had one small gas port. I bought a new barrel from Russells and found that the newer barrels had a slightly larger gas port, and they cycle both flawlessly. Even when shooting cheap Walmart shells.
Anywho, as mentioned, I would highly recommend them.