I've been with thinkorswim for about a month now, and they absolutely do have a superior platform.
They were introduced to me through Trade$ecrets seminars and very shortly the Trade$ecrets option software will be incorporated into their platform. This is analysis software with a live feed that will be available on an optionally purchased TAB at the top of the thinkorswim window. This is pretty impressive software and picks all kinds of potential positions out of the chaos for you based on the Trade$ecrets criteria which tend to be very risk-averse. It's not cheap, but it will probably be worth it. The time savings alone should pay for it in a few months.
Another reason for using thinkorswim is that they allow Trade$ecrets grads to open margin accounts where they otherwise might not be allowed to due to credit problems or inexperience trading. This was a significant factor in taking the course for me. (It also turned out to be a great course -- I'm still digesting from January...)
Trade$ecrets aside (and I'm not shilling for them or anything, they just were a great start for me), there are two other aspects of thinkorswim I like:
The platform is written entirely in Java and looks amazing as well as works very well -- nothing remotely like a Windows application about it.
Second thing is really first and that's execution. At a 2-day Vegas trading session put on for grads by T$, two brokers were present to take the trades, thinkorswim and Mr. Stock. While Mr, Stock was still having difficulty placing orders between the Bid and Ask an hour later and sometimes failed to fill altogether, thinkorswim was filling all day long in under two seconds. And you can tell them where you want it placed if you feel the need, but you probably won't...
I guess these guys were offering brokerage services to other brokers, ex-floor traders and experienced pros pretty much exclusively before they opened their doors to the public, so their facility was expected, but their elan about the whole thing was really a pleasant surprise. They have a very funny outlook about trading options ("BORING!"), and about themselves, that's a nice break from the stodgy crap you find on every other site.
They also have a great education section on the site with definitions and strategies and a lot of tools to help you get started and keep you afloat.
The software is free to try out for I think 7 trading days before they expect you to fund an account and the preview is a good idea. There are no scanning tools, though (at least until the T$ Tab starts functioning), so be forewarned.
They're right where you'd expect at
http://www.thinkorswim.com . Have your shockwave Plugin installed if you want to see the optional (!) incredible visuals they've got running on one of the best websites I've ever seen (and I was a Web Designer by trade).
Here's hoping you...
Seymour Return
PS: The support is excellent, too. They helped me out significantly when I had a wire transfer problem with my old broker and some issues with how to set up the account to include my wife a certain way, stuff like that. The managing partner was e-mailing me forms and generally assisting me personally, so either they have nothing to do over there or they're really big on crm.