I've heard some ARC but not those particular models. I've heard mostly their tube gear and it sounded great with Martin Logan speakers. The dealer also sells B&W. I found ARC with B&W not so pleasant to me. Isn't the D100 their digital power amp that retails around $2,500.00? If so, I haven't heard it but a friend is using one until he can afford some Edge gear and he thinks it's a great amp. I have all the confidence both pieces are good sounding but much of your result will also depend on speakers and source, as well as the stuff TS mentioned. So much of good highs or bass is subjective to each listener it's difficult to convey. I'd say the ARC tends to be a warmer and polite presentation. I also find that brands like ARC and Conrad Johnson, when they do solid state they don't stray far from their "house" or signature sound. If I were you and the price was right, I'd jump on it.