Once you have found comfortable cleats that feel good to play in, you are better off investing your time and money on training or high level competition, instead of spending an extra $100 on fancier cleats. Camby may debate this...
I thought I would share what cleats I use. At the moment, I own several pairs. I have a few pairs in the cupboard, buying when I see a sale rather than when I need a new pair. I am banking on the fact I will be playing ultimate for more than 12 more months (seems likely!).
Gaia Ion Flame
These cleats are well padded everywhere inside - easy on the feet. Probably good for those prone to blisters. It also means your feet don't move around at all. The upper is kind of plonked onto the sole - not much design to minimise the inevitable splitting of sole and upper.
Also, the bulk of the shoe and depth/position of the studs makes me feel I am a little more likely to roll over on my ankle. Available for quite a low price.
Nomis, an Australian based company, have a sale on now (the rugby league State of Origin models are now $100, down from $300). The Rapids are the cheapest in the Nomis range and are the newest addition. Nomis started with models only over $200 but are now entering the $100 price point too, after building an identity as a "deluxe" brand.
The Rapids don't have any special upper surfaces for gripping soccer balls in the wet or dry. But I don't kick soccer balls, so nothing lost there. Other cleats from Nomis (not these though) claim they are less likely to pick up mud on the cleats, reducing weight on muddy fields. So these ones still pick up mud. The inner sole is also cushy and removable. Basically these are conventional leather soccer cleats without Nomis' extra "technologies".
Nike Vapor Jet 4.2
Soccer boots are designed for running, turning and kicking soccer balls. American football cleats for big linebackers have protection, support and traction, while cleats for nimble wide receivers are designed for running and turning. They are also allowed to have a toe cleat (soccer boots aren't).
Asics Gel Lethals
Also, now is a good time to buy cleats, with some sports stores having mid-year sales. August to September are also good times when stores clear winter stock out to make room for summer sports gear.