I did like the sound of the REVEL Performas. They sounded very punchy and the Beryliuum tweeter brought out the symbols better. That is the only thing I am missing at this point.The Arcam Class G is more of a smoothed over colored type of sound. This may actually be removing some of that "cymbol" sound that you're looking for. Putting an external amp could help bring out that type of sound you're looking for. That being said, the new Revel PerformaBe series is absolutely excellent.
soix's recommendation of putting an "integrated amp" on the left/right pre-outs is meant to use the integrated amp for 2-channel sources. Just keep in mind that if hook up a source to this integrated, you will not be using the REL subs.