I used Earth for a few years. It seemed to work well with just about any site I tried with only the occasional issue, resolved by switching to another server.
They are pretty fast and have a lot of servers scattered around the globe.
Support is pretty quick for the most part.
I have had a few issues with the GUI client provided on some platforms. Could never get it to function on machines running Vista. It installs okay but will not make connections and throws some errors. Windows 7 and 10 it seems to work okay. Their support never had any solution even though they claimed it should work fine on Vista. Tried three different machines with same no-go result.
That said they have an alternative client "Viscosity" that does work just fine. Only thing is you have to re-enter your login for each individual server you connect to. Yes you can save that login but ONLY for that particular server. On the main GUI you can enter it once and not have to be bothered doing it over and over. I like that feature so was disappointed it would not work on all machines.
I stopped using Earth just this past week. Not because of any issues with the service but because of payment issues. Seems they are located in Turkey and their government made some new rules that basically pushed PayPal out of the country. That left many businesses in Turkey with few payment options. Earth is still in business if you have Bitcoin or something called "WebMoney" and I won't go tie my bank to anything or anyone that does not have the security and reputation of a PayPal so I was left with no method to pay to continue their service.
Me resignation from Earth was not by my choice nor by any fault of EarthVPN, it was all due to the nation of Turkey's finance minister.
UPDATE 2017: EarthVPN is now able to accept PayPal again !
I suspect their move may put a lot of strain on their internet based businesses.
If you use Bitcoin I do recommend Earth. I just hope losing PayPal does not make it so hard for them to continue that they fold.
Would be a shame.