I've had both the Lepai LP-2020A+ and the Dayton DTA-100a for several months. They were acquired mainly to satisfy my curiousity, and I am amazed at their performance and bang-for-buck factor. They've been used in my office system where they were auditioned with a wide variety of speakers. Short verdict: I prefer the sound and 4 ohm capability of the Lepai, but the Dayton is clearly more powerful and a little more "clinical".
I recently ordered a Topping TP60 with the intention of using it as a summer substitute amp in my main system. My main amp is a Bedini 25/25, which sounds great but can double as a hot plate. Since I live in Arizona, this can be a problem. My speakers are ADS L1290s, with stated sensitivity of 90db/1watt/1meter and 8 ohm impedance. I've been switching between the two amps for about a month now and feel that the TP60 is a great value (I paid $220 delivered) and will serve its purpose this summer. The Bedini sound is smooth, clear and shows a lot of authority in the low frequencies. The TP60 seems to be voiced to emphasize the mids and high frequencies. The lows are solid and tight, but a little too subdued. The other thing I noticed with TP60 was a slight midrange glare that I could hear when I pushed it hard. I never noticed any clipping, but always backed off the volume at that point.
I've listened to the TP60 with and without a preamp (Bedini & Nakamichi CA5) and prefer the sound with a preamp. Neither preamp has tone controls, so the next step for me is to drag out an equalizer to find out how much of the difference I hear between the TP60 and my 25/25 is due to frequency response anomalies. I don't have a scope, so my ears will have to do. Overall, I'm happy with my purchase. I hope my experience helps you make a decision, but as with any amp/speaker pairing, synergy is critical. As you may know, this amp is available from a couple of US retailers who accept returns.
Good luck!