I chose a .38 (well, OK, a .357 SP101 but I am limited to .38+P by Dept regulations) over my G26. Here's why.
My BUG is carried as a backup to my Glock 21 duty weapon and is also carried off duty. If I ever have to use the SP101, I can see a lot of tussling involved. I want my BUG to be 100%, dead on reliable, whether I am injured, fighting, in an awkward position, shooting weak handed only, shoving the gun into someone's ribcage, all of the above, what have you. To me, that means a revolver; no limp-wristing, no being pushed out of battery if pressed against a body, no mags to worry about, just pull the trigger.
For me, a revolver, with the curves and such, conceals a lot better than the flat, angular auto. If it prints slightly, people just see a gentle roll in my clothes and assume it is the fabric bunching up; if the auto prints, you see a flat plane or angle which, to me, screams "GUN!".
Don't get me wrong, the G26 was very good at what it did. I just decided that, for my particular requirements, the SP was better.
Backups are, like guns in general, very subjective. I like my SP as a backup/off duty gun; you or someone else might like the G26; someone else might like a Walther PPK or what have you. Whatever you decide, remember to practice, practice, practice, then practice some more. Practice weak handed; practice reloads; if your range will allow it, practice on your back and in any other awkward position you can think of that you might be placed/forced into in a fight. If it is a backup and you need it, chances are the fecal matter has already hit the rotary air impeller and you don't want to have to worry about reliability or your ability with it.
Bub