Is the Sig more reliable than a glock?
In my experience, YES. The only manufacturer that I have shot a respectable number of rounds through and NOT had a malfunction is Sig. P226 and P6 have NEVER had a malfunction and I have put more rounds through them than anything else.
Others I include in this:
Walther, Ruger, Glock, Taurus, and Springfield 1911 all have had malfunctions on me (and all more than once).
As for weight, the 226 might weigh more, but that is mostly because of the size of the slide. The aluminum frame is very light. Its definitely not like carrying around a full size 1911.