I just picked up a TS-590S as an upgrade from a TS-50S. It wasn't as much of a change as you might think. The TS-50S has a fair receiver in it. It gets better when you put in the Inrad filter and for CW the 500Hz filter as well. The 590 does many things the 50 wasn't able to do but the price comparision considered it would be hard to beat such a simple radio. Don't get me wrong the 590 is a good rig and I'm enjoying it. The whole idea was to get what was best bang for the buck. The 590 is lower in cost than a lot of the other rigs that have similar equipped features.
When I bought my Yaesu in the mid 90's, I excluded Kenwood from the list of choices due to its poor customer service reputation. The antenna system, among other factors, can allow most radios to function well, or otherwise. Height and lack of obstacles is ideal, but plenty of great contacts have been made on ground-mounted verticals, and temporary setups.