Ok I tried this RDP (the $4 plan) for two months. It is cheap, and it works OK. But be aware, if you use the cheapest plan (dont know about the others) you get what you pay. They assign 30-35 users per server. The connection speed is OK, sometimes its normal, sometimes it is slow. The RDP gets slow regularly and they reboot frequently, like once every 2 or 3 days maybe, thats what I felt. And finally 10 GB storage is OK if you start, but for me it wasnt enough.
Thats my experience, I think it is ok for starters if you have a limited budget. If you can pay more or you need a good stable service I would not recommend this plan.