We stayed at the Loves RV Stop in Hardin, MT a few nights ago. It was a very easy process from reservation to parking, etc. On the way to Texas we passed 3 other Loves RV Stop and none of them compared to the one in Hardin.
The key difference is the location of the RV Stop. Some Loves have it in an adjacent property, separate from all other traffic. Those are ideal and I wouldn't hesistate to stay.
Others are after thoughts, either taking a portion of the truck parking, or putting it in an area near the gas fuel pumps. These are typically back-in only and are crowded and very exposed to the constant traffic in and out. I would avoid these personally.
The one in Amarillo TX is an exception in the sense that it is separated from all traffic for the Fueling/Retail operations, but sits between I-40 and Loves along the access road. This is less than ideal, as the semi traffic leaving the fueling will exit along side, and enter on the other side. It also presents potential security issues being so close to the access road.
As long as you do the research before booking, there are some nice Loves stops.