ms180
I have an ms170 and it's ok. Had an Echo CS346. Stihl's wimpiest home owner saw is way better. I just sucked it up and got an ms200. Really no comparison. Will save me tons of time and pay me back quickly in both time and frustration savings. The extra power for same weight makes triple the price worth it for the pro. If you get into it seriously, you'll want to upgrade eventually.
The thing about a carving bar is not just the small tip with regards to detailing, but reducing kick back when working with the tip of the saw, which the small tip, going down to 1/4" chain, and carving chain, which is designed so that the back of the cutter doesn't hit the wood as it comes around, in other words it's sloped back more.
Stihl just started getting really serious about carving this year, offering their own bar, chain, and sprockets for a number of small saws. Echo's promoted carving for a long time now, so that's partly why you hear so much about them with regards to carving saws. They're light, but there's no comparison to Stihl or Husqvarna in terms of quality IMO.