Also talk to the instructors, go to different clubs and get a feel for them, I find people still get frustrated when I dont pick up seemingly simple things, but not as frustrated as I get with myself.
I'm a white belt in tkd but so much better, as I'v been practising for years, and playing catch up in in karate, i'm at brown belt and probably taking black belt next year. I started both when I was about 18, I got to green tags in tkd, and brown belt in karate as it was simpler as we dint really use kicks. so thats 20 years to get to this point as I'm 38 now.
Forget the arguments over which is better, the 1 that you like and suits you is the best for you.
I have sensory and coordination problems, I entered a karate competition recently, 1 of the people in my club was going on about how she looked stupid when she messed a kata up in the previous comp, I had a mind blank and messed mine up, didnt get to finish mine, at least she stopped going on about hers after that, in the kumite (fighting) I was clueless and lost, oh well.