Battery capacity after 200 load cycles - what is normal?

Keep in mind that with LiOH, it is not merely cycles. Mere age is also a factor. A LiOH starts loosing capacity the moment it is assembled, even if just sitting on a shelf. Since you don't know how long a battery sat in storage before you bought it, it could already have a fair bit of age on it.

Also, in my experience, the decline in capacity is not at all linear. Once it really starts to show (enough to really affect your useage), the battery will go do hill more and more quickly. So, sorry to say, but from what you posted, I would not be surprised if your battery now starts to really begin showing a drop in performance.

That's also why I avoid bargains on eBay and such. If you are buying used warehouse stock as "new", but that "new" is a couple or more years old, then it is already well past it's prime, whether actually used at all or not.

Check out the following:

Apple notebook batteries – maintenance and troubleshooting>
http://support.apple.com/kb/HT1446 Apple Portables: Tips for maximizing your battery charge
Maximize the battery life

I've never heard, nor read that Apple "guarantees" anything like what you say. Apple claims:

"Battery Lifespan
For Apple notebooks with removable batteries — such as previous generation MacBook and MacBook Pro computers — a properly maintained battery is designed to retain up to 80% of its original capacity at 300 full charge and discharge cycles. You may choose to replace your battery when it no longer holds sufficient charge to meet your needs."

There is not guarantee mentioned or implied in that statement. Whether any particular battery still has 80% life at 300 cycles is anyone's guess. It depends entirely on the manner in which it was used, operating temperatures it was subjected to and so on.

IMO, if you are over 200 cycles and you are starting to feel that the battery is not holding sufficient charge for your needs, it's time to shop for a new one. Batteries are a consumable item - they will fail with enough time and use - that much is guaranteed. It is a function of unavoidable internal oxidation and degradation of chemical components, not of the "smart" battery control circuitry.