MB is spot on with these two options because this is exactly what happened to me. I bought a MS 390 thinking it would be the only saw I'd need. And I was right. Unfortunately, I DID NOT RUN AWAY FROM AS!!! I kept on reading and soon became CAD infected from head to toe. So I found a clean, used 260, sold the 390 and got a new 460. (And a few more, but that's another story!)
The 390 cut very well in hard, dry, 18-inch oak--but it's nowhere close to performing like the 460. And the 260 sure is nice and light for trimming little stuff. If you get the 390, do a muffler mod and richen the carb. Get some Stihl RSC chain instead of the RSC3 safety chain. But above all else, if you get a 390, RUN AWAY FROM AS. Because you'll be wanting more all too soon, just as I did.
Olyeller