API connections/queries limits to Dynadot, Namecheap, Onlinenic

[xtmoney]

i would like to know what are limit connections/queries for dynadot,namecheap, onlinenic
and which of above is faster? I'm asking because will write multi thread desktop app catcher but want to be sure which one is the best.
dynadot - want 500$ prepay - is it worth?
namecheap - want 200$

 

[Volf]

I'm interested in this too! Somebody help?

Update:

Dynadot API: For COM/NET domains, you can only check or register the same domain 10 times every 100 seconds + have to wait for a response before sending a new query.
Moniker API: 1 query a second; Slower queries must be finalized before new queries are submitted.
Fabulous API: 1 request per second + some other limitations that they will not discuss

From what I read, Dynadot is one of the fastest.