Revel F12 amplifier?

I own a Revel Concerta system with F12 fronts, C12 center, M12 surrounds, B15a sub. Moved into an apartment, now can only use subwoofer sparingly for HT purposes. As a result, doing a lot more full-range listening with F12 fronts. Current receiver is Integra DTR-7.8.

F12's are rated as 90.5dB sensitive with "nominal" 6 ohm rating. What benefit (if any) could I realize from using an external amplifier versus the amplifier in the Integra?

My dealer carries Anthem and Rotel amps in my price range. He suggested Rotel RB-1552. In the $1000-1500 price range from those two brands, what else should I consider? Is it worth considering something like Anthem MCA 20 even though I don't have balanced outputs on the Integra receiver? Thanks for your help.
I think adding a seperate amp aside from the amplification provided in the Integra would add considerable sonics. As the power supply in the receiver would be able to dedicate itself to the duties of a pre-amp. And the amp would then become a new issue as what amp to go with. Personally of the 2 you list I would choose the Anthem. But are you looking at 2 channel or 5 channel amps? From what I see the 1552 is a 2 channel amp and the AVM 20 is 5 channel? You might look at used here on AG and see what is available. I saw a Mcintosh MC206 but I think it was about 2500. I saw a few Sherbournes recently in the 1000 range. Sherbourne is a good amp, in case you don't know they are a company of ex-McIntosh folks that build a darn good amp for the money.
There are a number of used multichannel listed.
Theo, thanks for the response.

Due to cost constraints, probably just looking for a 2 channel amp for now. The Anthem MCA 20 is a two channel model as well. I would amp the main right/left F12s and leave the Integra to take care of the center and surrounds while watching movies.

The Rotel retails for around $899 whereas I think the MCA 20s retail for closer to $1200-1300, so it is difficult for me, as a first time amp buyer, to know where the point of diminishing returns would be for my setup.

Thank you for the brand suggestions as well. With all of the products available here, it is easy to overlook a brand that might be right for you.