"We strike, then cloak and sit perfectly still in some corner for a long time, then strike again."
Focus being that they were cloaked and did nothing offensively for the bulk of the match's time.
Overall, I'd say Romulan tactics are heavy on cloaking and less direct combat (From the little I know of them). Where Klingons seem far more for using cloak to get in and hit hard then simply to hide and watch.
I'd have to disagree with you.
Far be it for me to dispute a perception, but what makes an attack "Romulan" (read: cowardly) is the overkill factor coupled with the "letter of the law vs. spirit of the law" mentality they use to justify their attacks. See Picard's intrusion into the Neutral Zone and Tomalak's justification for announcing his intent to destroy the Enterprise.
Strike, cloak, wait for opportunity, strike again" is actually a pretty basic ambush tactic. It's viable, doable, and everyone does it in one instance or another. Besides, "direct combat" is something I would call the strike part of that equation... they're vulnerable and firing. It doesn't get too much more direct (outside of suicide) for a Bird of Prey by design.
Ambush tactics are an effective, working strategy that can win a conflict. I agree, it sucks when the entire opposition is made up of these ambushers, since they ALL wait for that opportunity, but they're about. Raptors can and do do the same thing, albeit minus a battle-cloak. Cruisers tend to lessen than tactic, as the sheer staying power of a cruiser tends to allow both Raptors and BoPs free time outside of cloak to fire on any targets they want.
Romulans using radiation, poison, other stuff that damages/destroys their enemy without engaging I would consider cowardly (and, naturally, "Romulan"). Striking from a position of stealth and returning to said position is akin to a trapdoor spider hunting prey; it's just what they do, and isn't dishonourable any more than it is honourable.
What is honourable/dishonourable is what they do in that time, how they do it, and how they receive the outcome.