SPIRIT coming to DFW

I've never used Spirit airlines. I've heard they're cheap. I've heard they charge for carry-on bags. But starting in May they are flying from DFW to LAS twice a day. Some of the initial fares I've seen for the summer are super low. Some mid-week rates are less than $100 per person round trip. They also offer the $9 club which reduces some fees and offers some promotional fares. Might or might not be worth the $60 to join. My question for those of you who have Spirit in your airports is this:

Is this going to be an amazing advantage that reduces the price of my trips and allows me to go more often for the same money? Or am I going to be cursing through my first trip and going straight back to AA or US Airways?

I appreciate any thoughts before I get too carried away with these low fares...

I am from Dallas also and been watching this lately. I looked up their vacation packages vs. USAirways. They don't really seem cheaper but lots more hotel options. Their airfare though does seem to be a lot cheaper to get to Vegas from here so I too would like to hear from others who have flown on Spirit.

Have used Spirit airlines a few times, but not since they charge for carryon. You pay extra for selection of seat, any carry on ither then one small item, charge for food, pop, water. Will only accept credit card to pay for food & drinks. So it will add up from original price. Sometimes still a better price, but some of the seats makes it feel you are packed in a sardine can. DJH