my playstyle varies based on the speed of the game and pacing of the gameplay. I normally play support characters or the "jack of all trades" because I like to help people be awesome and I do not always commit the time to practice my aim to be proficient with assault classes. Ultimately I think it boils down to how many choices I have during combat.
Global Agenda: This is really the only outlier here because I played the Assault almost solely. I found it enjoyable to really press the enemy lines while the medic players kept me rolling. I normally play the support but I struggled with the medic class and did not feel like I had a lot of options. The assault felt natural as I knew how not to overextend and keep my medics alive. I felt like I had more control as an Assault; less control as a Medic because teammates often dove the control points which in GA was always suicide. (I stopped playing because pvp queues were too long).
Overwatch: Of course Mercy comes to mind because she has the option to either heal or buff allies. The choice of switching between buff/heal during the fray of combat was always there. Using improved damage at the risk of teammate death and if I trusted the teammate to not miss their shots or overextend was enjoyable. Mercy's pistol also dealt a fair amount of damage too. I also played Zarya because she's a strong support character capable of preventing a lot of damage and deaths while in turn retaliating with high damage output. (I stopped playing because too often the team strategy was to wait for ultimates to be charged then dive in; I often felt like I was playing with a bunch of chickens who didn't trust their support and put too much strategy on their ultimates).
Firefall: really I solely played the medic class from closed beta to shutdown. I could gear up for full healing or mixed damage. Jetpack mobility gave me an enormous amount of maneuvering choices and damage evasion. Players seemed to have a general sense that overextending is bad however Firefall allowed medics to gear up for dive ins which was totally exhilarating (and when players recognized their temporary pocket medic...some heroic moments there) [overheal was sooo good]. As a medic I found great enjoyment learning my teammates on-the-fly; I had to understand if they were combat hungry, timid fighters, good shots, all so I could change how I maneuver, gear up, and how I chose to support them so they are the best they can be. I found FF's medic to be the best gameplay experience in a shooter. I could heal teammates, assist in damage output, and risk my jetpack fuel for improved benefits at the cost of being stuck grounded and more vulnerable.
I am extremely glad Firefall abilities will return for Em8er.
Bio-Rifle for damage and healing (would swap damage output for overheal or damage buff depending on whats happening).
Healing Wave for flash healing and pushing enemies. Also great for delaying damage by pushing enemies off elevated surfaces.
Healing Ball useable for short distance healing. Also useful for long distance predictable heals down hallways and for teammates who are combat aware enough to jump and catch a long "hail mary" pass.
I wouldn't necessarily call myself a pocket medic exactly. I keep my eyes open for teammates that need help and if I believe the person I'm following will survive until I come back I'll detach in an instant. I'm more of a "who needs me" and "who has promise" medic. I try not to spread myself too thin which is another choice in itself; I aim for keeping my team confidence and moral up but will gladly dive in if you can handle the pressure! I'm there for YOU! o7