Great for hosting and domain names
I've had my .co.uk with another registrar for more than 15 years, but the level of support and the lack of any understanding of what bulk domain name owners require has lead me to start moving my portfolio over.
I have hosted with 20i for more than a year now with zero problems and only just started moving my names.
The support is responsive and the transfer process is seamless and easy.
The cost of domain renewal is 50% lower and transfer-in is free, adding another year to the registration. You can't lose with that deal.