Not really, there was the 261, a de-tuned 262xp, not a pro saw, and there were a few others.
The 5 series is going to be the WHOLE new lineup, pro and non pro. The 575xp is the first run of that series. The 570 is a non pro saw based on the 575xp, like the 262xp and 261 mentioned before. Same saw, different jug.
I have a 51 that I put 55 top end just for fun. They don't have the power to weight ratio of a Dolmar 5100 or 346XP but they hold their own. I was impressed at how simple & straightforward they are when it comes to teardown/rebuilding. Just a good, basic design. I've been running 16" with Stihl .325 RS chain.