Derek Hollan wrote...
Do you feel there is enough of a spread of different classes to satisfy a variety of play styles?
I think so. The 6 classes offer varying degrees of combat, tech, and biotic powers. Within those 6 classes, I find that each character also work to satify a variety of playstyles, and with each DLC's new characters there are even more possibilities.
For example,
to me, the Infiltrator has always been about staying back and sniping enemies. Generally support fire, whether Human, Salarian, or Quarian. But with the addition of the Geth in Resurgence, whenever I play him, I feel so... aggressive. With Hunter Mode on, I feel like I'm ready to go slay everything like an evil assassin. It's such a different type of experience for me. Experiences and opinions differ from person to person, of course.

Another example is the Engineer, which again,
to me, has always been more of a support class. But with the Male Quarian Engineer in Rebellion, I feel more like a combat engineer than a support engineer and I play more aggressively, flinging grenades and sporting a Saber.
I can only presume that with each subsequent DLCs, we'll get more and more variety.
Derek Hollan wrote...
Do you feel that any one particular strategy or play style outshines the others?
I don't feel so. There are characters and/or builds that can handle certain enemies better (I'm thinking of tech powers against Geth, or biotic powers like Stasis against Cerberus), and there are those that are more "general purpose" like the Soldier and Sentinel, for example (love the Turian Soldier with a Revenant! And the Jack of all Trades Turian Sentinel). If you're running a specific lobby, then you can choose your class accordingly. If you're running an Unknown/Unknown lobby, then you'll have to be ready for all eventualities.