decision...to get a triple or compact double

[Grog]

Triples tend to have more shifting trouble than a double or compact double.

I don't think that's universally true, but it seems to be so in the lower range of the spectrum. I've got an Ultegra triple and I've had no issues worth mentioning over the last 4 years. But I think it would be different with Tiagra, and as other posters mentioned I would definitely avoid Sora... Sad but true.