I bought a Performer brand new from Home Depot and it was before I did research on them and I ended up with one that doesn't have the gas assist. From what I've read it really is handy, but lighting with the Weber starter cubes is super easy too.
But I guess if you're grilling a lot, after time the cost of cubes vs. the gas assist will start to close and the propane option will end up being cheaper.
No matter what you get though, you'll love it. I have got so much enjoyment from my Performer.
Weber Spirit E-310, Weber Performer, Weber Smokey Joe, Mini-WSM, ECB Electric.