Shorter and more reliable because it has a straight line feed and does not use an elevator to lift cartridges from the tube magazine to the chamber, there are far fewer parts to wear out.
The Model 61s have an appeal if you also favor Model 12s and Model 42 pump shotguns but they are also longer than they need to be and prone to jamming if they have been heavily used.
They are also quite overpriced on the used gun market because of the collector appeal, running about $300 more than what you will pay for a comparable Model 63 semi auto.
What they will do, if they are working correctly, that a Model 63 will not is feed shorts, longs, and long rifles, High Velocity or Standard Velocity, that is if you want to risk ringing the chamber with a big diet of shorts and provided that hasn't already been done.
Model 63 rifles function best with high velocity loads and avoid CCI Stingers, the case is longer than most Model 63 chambers, same goes for the 61s and 62s.
The longer cartridge case can lead to firing out of battery with the usual split case and ejecting hot gas and material along with occasionally blowing the extractor off the rifle.HTH