Since everyone who is serious about playing well needs to practice long tones with a tuner, I thought I'd share my experience with contact and mic tuners. There is a huge difference between the performance of inexpensive contact and mic tuners, surprisingly in the contact tuner's favor. It is a common misconception that contact tuners aren't suitable for woodwind instruments because the body vibrations don't carry the fundamental. The fundamental registers quite nicely on the bell of a tenor from low Bb to altissimo A. If you bend the pitch, the contact tuner will follow it accurately.
The mic tuners I have used tend to twitch a lot from some sort of spurious acoustic response, even in the absence of ambient noise. It can be quite distracting. I have found a contact tuner much more stable, with a result that my long tone practice is much more effective and certain with regard to intonation. It's also nice to be able to move around a bit without worrying about pickup or viewing angle when practicing long tones.
One caveat is that not all saxophone bells are created equal, so if there is a stress/resonance issue it may cause a problem. But the benefits of a contact tuner make it worthwhile to gamble the $10 - $15 it takes to get a contact tuner and get free of the hassles of using a mic tuner. A cheapie will do the job just fine. Super fast and super fine are not required.
Wow - this is a very interesting post. I've never considered a contact tuner having used the normal mic tuner for more than 20 years. I will investigate more! I posted a video sax tip about using a tuner that you might find helpful here: http://youtu.be/DrEMv6QCUzI