Does it generally take very long to master this and do experienced tailwheel pilots still have the occasional meander?
mm,
Tailwheel flying is not a skill just for the supremely gifted. If it was, we would have had a lot less pilots before nosewheels. Plus, as further proof, even I can do it.
Nosewheel airplanes don't give you the quality feedback when you do a less than quality job of lining up the airplane with its direction of travel. Tailwheel airplanes do. Once you get the hang of it, it's not so bad. Remember, there are no squirrley airplanes, only squirrley pilots.
As far as the occasional meander, you betcha. Just like any flying skill, the best measure of a pilot is not necessarily doing it perfect every time, but more so the ability to recover when you have screwed it up. Just don't let it go too far! And if you have let it go too far, and have flying speed, get them wheels off the ground! Then the problem goes away.
I'm a firm believer in training on hardtop. Crosswinds and all. Everybody is different, but I've seen guys who are very intimidated by pavement. Get that trained out early and it's no big deal.
-- IFMU