It's interesting that this topic has been posted now because I just recently decided that once I get to $1500+ and have consistently beat 50nl on pokerstars i was going to ship the roll to FT and grind out their $600 first time deposit bonus playing 50nl. This way it will clear faster and I can ship the roll back to pokerstars ASAP. The only reason I want to do is this:

1.) To build my roll a lil quicker (who wouldn't? lol)
2.) Try out a new site software. (who knows if i like it enough i might just stick on FT)

What you have to remember is that #2 is the whole point for sites to have bonuses. To attract new customers. I was also considering doing the Ultimate Bet bonus later on, too. There's simply no reason to not try out a new site if they give you a bonus imo. Unless obviously you like the site you are on SO much that you refuse to try out another.

These are just my opinions, all subject to change at a moments notice lol. (<-- Hmm... new sig? lol)