I don't like blades and haven't used them in many years.
It seems to me that rotary works a little better than foil if you have heavy beard growth (i.e. if you haven't shaved in a couple days), but otherwise they're about the same.
Get a unit with a trimmer, or have a separate trimmer, for really heavy growth. It's also good for sideburns, neck hairs, etc.
The manufacturer's main scam is that the rechargeable cells aren't easily replaceable. When they crap out after a year or so, most people buy a new razor. With Norelcos you can disassemble the razor and change out the cells (solder tabbed Nicad AA's). You can get tabbed cells from batterystation.com or wherever.
After about 3 sets of replacement cells over a 5 year period, my Norelco pretty much completely stopped working (internal charging system crapped out or something). I bought a Braun (forget what model) just to try something new. It worked fine for the usual year or so, but oops! The cells are installed in some way that you can't get them out without breaking something (no normal assembly screws).
Another hassle with rechargeable shavers: if the cells go flat, for most models, you can't shave until you've at least partially recharged the cells, say for 10 minutes. If you have to shave before running out the door to work in the morning, you may not have 10 minutes to wait for your razor to become usable. A few of the more expensive models are specifically labelled "AC/Cordless" which means you can use AC power even when there's zero charge on the battery. I wouldn't buy another cordless shaver without this capability.
After the Braun failed I decided I was simply fed up with the intentional product obsolescence and I couldn't think of any times I'd really needed to shave with no AC power available. So I bought a Remington corded shaver which I'm reasonably happy with. I'd say its shaving action isn't quite as good as the Braun's, but it's terrific to be free of worrying about the stupid batteries. The AC cord is really not much of a nuisance since there's an outlet close enough to the shaving mirror in most bathrooms.
Finally, for convenience/travel/whatever, I have a cheap Sanyo shaver powered by normal (non rechargeable) AA cells. It has no trimmer and only one foil head, so it's not that great a shaver. Unfortunately, there seem to be no good shavers that use replaceable batteries. Note that Braun also makes a cheap AA-powered razor, but it's veven worse than the Sanyo.