I have been on this forum & the old one for a number of years. I am of the opinion that the base gasket issue is statistically a non-issue. It certainly can happen, but of all the bikes represented here, only a very few have been impacted. So far my 06 has been ok. Given the fine post on "Base Gasket replacement" I would not be in fear of having to deal with the condition. Gerry
I have a 2005 that leaks about an ounce between changes. Not worth worrying about, or the time and money to change the gasket. That said, whether you choose to fix it or just ride it, you will love this bike.
Forums, by nature, contain issues that people are looking for a solution to. They're, generally, for problem solving and therefore you see "lots of problems" when reading through them. I've never started a thread that said "2004 TW200, base gasket still good". It may seem they ALL have issues because you see issues a lot on here, but, I'm with Gerry, if all of us without issues posted we never had issues then the pendulum would swing in favor of it as a non-issue. But yes, that year is known to have an issue. How much of an issue, I don't know.
And to boot, if it does affect you it's not a hard fix. Go for it and budget a fix if you ever have to cross that bridge.
Usually what happens with me is I get hesitant because of known issues but then finally make the purchase only to crash the thing and have bigger fish to fry.