Can the forum software you use affect your members?

In the order if things matters for me.

1: These guild networks have horrible forums with slow respond times. Amount of advertisement isn't to much though. However due the lack of Polishing and performance it really shakes me off.
2: Other free forum hosts
3: Skin VS Advertisements: I hate it if the advertisements are in my way when I'm browsing a forum. This really shakes me off.

After this I'm calculating my preferences in this order:
1: Does the niche interesses me?
2: Does the niche has potential(Paid forum software is a multiplier)
3: How easy is the forum to use?