My personal opinion? MB.
Had both, Viseeo MB2,MB4 and MB HFP cradle.
Problem I had with Viseeo was that it often did not autoconnect with my phone. had different phones and they all had this problem. Usually you don't notice this rightaway, so I had to stop the car pull out my phone from my pocket and manually connect to phone to the cradle. In my opinion this makes the cradle useless. Eventually I got so fed up with it that I ditched the Viseeo and got myself an original MB cradle. Worked flawless from day 1. Only problem I had with that was transferring the phonebook from my Android phone. Solved that by installing the old IrMC/SYCH software on the phone.
I have the MB puck in my SLK, and it works really well with my iPhone 6 (although I think there's a limit of something like 200 contacts that will sync with it).
My step-father has a Viseeo version for his E-class, and he's had a number of issues with both initial sync/pairing and then the reliability of it auto-connecting to his iPhone 4S... mind you, I can't testify as to whether those are user issues, or issues with the product!
Forget the puck. Do an eBay search for Mobridge m2.Pro most. There are a couple up for auction. They work with any Bluetooth device and allow you to use the steering wheel buttons. Easy installation too. Highly recommended.