For the times that I've needed them, I've had very good experience with them. The mere fact that they are native English speakers sets them apart from the pack.

If your questions are about your Apple hardware or software, they will certainly help you. If they're very specific to a third party product, then they'll point you to that third-party product's support. It's simply not possible for a technician to have expertise in every piece of software under the sun. In many cases, they will make a best-effort (particularly at the Apple Store, where they can work on it in-person), but you can't expect them to hold your hand through every imaginable situation - even when it's related to products they don't make.

If you thought that you were buying into your own personal help desk to avoid having to do any research on your own, then you thought wrong. That's the reason why forums like this one exist.