Currently any captain is equally happy and proficient in any class off ship. It is a thing of beauty. I think the Sci captain skills bring a bit more to the table than the Tac, but hey that's just me saying so. It's also fairly hard to mess up a general purpose space build if your wish to try out different ship classes. Just keep in mind if you are leaning towards a certain class of ship and you wish to maximize, you need to spend captain skills accordingly regardless of your captains class. And you may need to use the exchange or trade for BO skills that your captain cannot train if you do wish to mix ship and captain classes.
I went with one of each captain. And one of each ship class for each captain. So enjoy the variety I say.
I'm having a good time right now with my Tac in Escort ships. It's very freeing to be able to just run into a battle with dual heavy cannons blazing and destroy everything before they have a chance to respond!
Tactical, in my opinion has much better and funner ships, and better ground skills
Nobody has 'better and funner ships' since any class can fly any type of ship (for their faction, of course).
In my opinion, Tactical player skills are useful, but pretty boring, as they're mainly all variants of 'do more damage' on both ground and space
Science and Engineering though, have both offensive and defensive skills, and ones that work differently to accomplish them (Turrets, Orbital Strike, Miracle Worker. for Engineers, Dampening Field, Photonic Fleet, Nanite Infestation for Science) and that includes their kits as well.