It's Vnish.com, and don't expect to receive any lower rates just because you downloaded from the "official website" you are going to get the same rate.
according to my contact most of them offer a dev fee of 2.4%
I doubt the 2.4%, though; the fee is more so variable depending on a few things, but it's anywhere between 2.2% and 2.8%. The agreement says so, and obviously you are more likely to be paying the 2.8% than the 2.2%.
If you want to go Vnish, you may as well just get the AwesomeMiner distribution. I don't know if that changed or not, but in the past, if you used their distribution, you could use the software for free. Awesome Miner is a perfect all-in-one monitoring and management tool, which I personally use.