both guns are great,
Sig 226 - shoots better than glock 17 but more expensive like 40% or more expensive.
Glock 17 is cheaper and is alot esier to detail clean , also you can upgrade it easily yourself. with right part changes it performs better than the stock sig226, thats why most of people I know who competes uses glock lines, I rarely see sig226.
also sig226 is alot hevier to carry compared to glock, but sig is so easy to shoot because the handle is contoured to and points straight to the target, and its trigger is more lighter thats why your shooting groups are better on sig.
But then if you Master the glock handling and trigger you will definitely love it.
so maybe I can say if your new and not planning to shoot too much - stay on sig226 its a great gun for new shooter.
but if you plan to go beyond that train on glock.
also try to check on cz75 lines they are great guns to consider and cheaper too, but the parts are not easy to upgrade
I would recommend Hoffman they sell (New) 226 and G17 cheaper than any other store in CT.