I was thinking of buying an SLR-104UR but NOT SBR'ing it. My question is given the large difference of the gas system between the 104UR vs the 104FR (port location etc) is there any reason why I should reconsider this option? Are there any reliability concerns? Are the krink style sights significantly worse given the shorter sight radius vs the 104FR?

Thoughts and opinions from those who have handled both?

If you're not going to SBR I don't feel that the UR is going to give you an advantage over the FR except for maybe looks. But with the long barrel/faux suppressor, I'd argue that it doesn't win in the looks department either. The UR would more than likely be more desirable to buyers in the future if you ever decided to sell it.

Apparently, from another source it was explained UR's are overgassed as they are meant to be SBR's. Makes sense.