I had both types braces. I had the conventional kind back when i was in middle school to correct the upper and lower jaws. After about 8-10 years, my lower front tooth wasn't in line anymore - it had moved forward. The dentist said there was a higher chance of chipping when i chewed, so i got invisalign.
I only needed invisalign for the bottom jaw and my orthodontist said it would not be any more expensive to go with the invisalign. Invisaligns were awesome. They set me up with a 10 mold system where I'd wear a mold for 2 weeks then move to the next one. In about 3 months time, my tooth was back in place.
I would say that painwise, invisalign is the way to go. There is always soreness whether you use conventional braces or invisalign. But you won't get the sores on the inside of your lip. You don't have to worry about long ortho visits (it would only take 2 minutes for him to check on me and give me my next set of molds). Also, the visits to the ortho are a lot more pleasant. No more tugging on your teeth. The best part is that you can take the braces out and eat whatever you want. They don't affect your speech much either.
Whatever you do, make sure you wear your retainer. I have a retainer that is basically my last invisalign mold (If I were you, I would avoid having them cement in a wire retainer because they don't work well with gum or carmel, etc). I wear it every night. It's no inconvenience at all. It's definitely worth the effort to make sure you won't need braces again.
If invisalign is roughly the same price, then definitely go with them over conventional braces.