uDAC and Little Dot I+.... good match for Grado SR80i?

Hey all, I recently got a pair of Grado SR80i (I guess you could say these are my first real headphones). I've clocked about 40 hours on them and have noticed some pretty substantial changes in sound quality through the burn-in period, and expect only greater changes to come down the road.

I've owned a NuForce uDAC since sometime in March and have loved it. I'm running WMA lossless ASIO4ALL via Foobar2000 and am loving the results of the SR80 through the uDAC.

I'm wondering, though, would a budget headphone amplifier like the Little Dot I+ improve the sound quality in a more than marginal way? The Grados are probably being driven to their potential by the uDAC, but would a dedicated headphone amplifier and using the uDAC as a DAC only bring any marked improvements or be suitable for the SR80i? I just wanted to get some opinions before I put another dent in my wallet. Thanks so much!

Thanks for your input, everyone. This combo is looking more likely as I read more.

@ s4one: My volume on Windows and Fubar2000 is set to max level; on the uDAC, the volume knob usually sits at 9 o'clock and is usually at a comfortable volume except for "hot" albums when I take the volume down. Keep in mind I'm running the SR80i from the uDAC only at this point. Some of my albums which have quieter and more dynamic mastering jobs usually allow me to take the volume knob comfortably to 10 o'clock.

@ maverickronin: The uDAC has a dedicated headphone out, but I can't vouch for whether it functions primarily as a Line Out; my understanding is that the uDAC is simply a DAC with an integrated headphone amp, although it cannot function as simply a headphone amp (although it works as a standalone DAC, which is what I'm getting at).