There are so many ship types from so many races, I have yet to grow bored with them, just the change of eras changes tactics, what works fine in early battles may not be so good in later scenarios.
I will eventually get round to MP, I have found over the years that live opponets are far more fun then any AI, as they can be both brillaint and inane all at the same time.
But the thrill is always there, I recall, many years ago, being caught by a Klingon squadron with just a single Kzin CV (this was SFB of course, the board game). The Klingon player was very happy (this was a tourney at a convention) because he was sure his three D-7Ks would smash my CV in no time. Seems this fellow didn't understand just how danderous fighters were, nor that Derfacs Dusruptor fire is effective at long range, as he was busy overloading his disruptors, I knocked down his shields with the fighters and let long range disruptor fire tear up his ships. The guy started to panic, never having seen this kind of tactic, and he was good as dead. I sent two of his ships to hell, and his third barely escaped by acceleration.
The moral is, of course ,is its one thing to beat the AI, beating the living is something else entire.