If you're going with plasma, be sure to get the +plasma Embassy science consoles as well.

Mk X gives you 8.4% plasma damage per console. With two consoles plus the 2-set Romulan weapon bonus, you're looking at a 24% increase in plasma damage. Almost another tactical console.

Sticking it on an Fleet Advanced Escort or Fleet Defiant will pretty much give you the equivalent to 6 attack consoles.

I'm thinking of doing that with my new Science officer I made.