The problem with this question is that people went and bought some battery and if it works, they will say it works perfectly and is so fine and superb. Whereas the factual situation is pretty much that any battery with the correct specs, unless it happens to come with a manufacturing defect, works equally fine. I mean, longevity and failure rate differ, but for that you'd need statistical data not one-by-one stories on the Internet.
If you buy a good quality battery (Yuasa works fine) and take care of it during long non-usage intervals (Battery Tender works great), your battery should last 6-7 years......as long as your charging circuit is operating as it should.
My original battery lasted four years, yes I use a battery tender always, b/c the weather can get a little bumpy around here. I bought a replacement battery from Batteries Plus about $93
Removing the battery is pretty well straight forward. Putting the new one in, not so easy, the battery rests kind of up under the back end of the fuel tank so you have to fiddle around to get it in. I don't understand why they made it so difficult to reinstall. The good news is once you get it in there it will not come loose because the back of the tank holds the battery securely in place. Good luck getting the rubber strap back in place.