The shield is hard to beat for concealed carry ease. It is great gun after a trigger job. The glock 19 would probably be a good option for you, not as easy to conceal but better capacity as well as glock reliability. I'd recommend getting hands on time with either one before you buy. The shield may be difficult to get ahold of.
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If concealibility is your main objective (as I assume because you are considering the Shield), I would say Glock 26. The 19 is slightly bigger, however the 26 can take the full-size mags which can be carried as reloads.
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The Shield is going to be easier to conceal. The problem with the Glock 26 is that it is still pretty thick.
Personally, I like the Shield and would take it over the Glock 26. However, the Glock 26 does have the option IIRC of using other Glock 9mm magazines. Not to mention standard capacity is better than the Shield.
Either seems like a pretty good choice. If you can do a side-by-side comparison you might find it easier to make a decision.
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