I have been using Rage4 DNS for various projects for the last 3-4 years and I guess I decided to write a bit about them :D
Reliability (5/5):
In the past 3 years I don't recall any downtime caused by their DNS, at least one that I'm aware of. Even if there were any problems that I didn't hear of, they must have been minimal.
Features (5/5):
Maybe I'm biased here, but they have just everything that we needed + some extra stuff that looks nice but I never looked into.
GeoDNS Routing (5/5):
There were some problems in the past cause by Google's DNS that broke their GeoDNS routing, but it has since improved. Except for China, the global routing is almost always spot on. Also their routing configuration is incredibly powerful.
Price (2/5):
I am not sure where they pull their query counts, but these are incredibly high. They changed how the queries are counted somewhere down the road, but I'm still not sure if these numbers are correct. On top of that, their current tier is 2€/mil queries which is absurd to say the least. So 50mil queries is 100€/month. After that the price is 1€/mil which is still pretty damn high, especially considering that Amazon Route 53 charges ~0.615€/mil from the start and then ~0.3€/mil. And this is ONLY if you use GeoDNS, otherwise services such as Amazon or DnsMadeEasy are even cheaper. Only at the 2500€/month does the service really get viable if you are a huge user.
The free tier is nice, but it doesn't last very long, especially thanks to the weird query counts.
I must point out that Rage4 was kind of enough to offer us the old price of 1€/mil even for a new domain, but I'm comparing the pricing listed on the page here.
I would give this 1/5 if there wasn't for their FREE tier. For a single site with a lot of bandwidth, their DNS is multiple times more expensive than the server itself.
Performance (3/5):
I thought their performance was quite nice until recently really when I did a few more tests to see if we can reach a similar performance with less servers. I noticed that queries take anywhere from 30-1200ms with them depending on the location and maybe.. cache? It's usually around 30-300ms in EU/US. We are now testing our own solution that with only 3 anycast servers on BuyVM decreased the resolution time in the US/EU to ~50-150ms and in Asia it's slower, but approximately the same in some locations.
I'm not sure if this is caused by the GeoDNS lookups, but it's sometimes quite slow.
Support (5/5):
First, I must say I'm quite easily satisfied with support. They always responded fairly quickly (within a day?) and offered helpful advice and as I mentioned allowed us to use the old pricing tier of 1€/mil. I'm not very fond of one-liner responses, but in the end I always got what I wanted.
Overall I'd say I'm quite satisfied, but @gbshouse drop your price! :P