Seriously though, all joking aside, I think the question is a bit hard to answer because there are so many variables. What is the wx radar telling you? How does the development look? Is it a nice day or are thunderstorms imminent with a fast approaching cold front? I can honestly tell you that in a 777 I would not think twice about it on a normal day. In a Super Cub, I will be avoiding it no matter how nice a day it is. In a climb, you may not even see it if there is an under cast layer and no real moisture in it to reflect back to the radar.
I have to assume that because you asked about airliners or jets that the Super Cub scenario doesn't apply. But put it this way, If Air Canada were to deviate around every TCU topped at 13,000 feet, ATC would go nuts. However, if there are other indicators present, like a cold front or fast vertical development, or better yet, a pirep, then most would be looking a little closer at the available options and then like yycflyguy said, go through it anyway!
Judgement call.
