First off, I still don't think the ART is a full tube preamp. I have never heard of a true tube amp anywhere near that cheap new or one with a Tube warmth LED meter.......
As for the component comparison, there is more to it than that. I'm not gonna waste time explaining all that - just use the search function.
Lastly, the listening test you provided was with $10 mics. So, I guess if you are gonna plug a $10 mic into the pre, then heck, I wouldn't even waste my money on a DMP3.
I have used nearly all of the pre's mentioned, and then some. A lot more in fact. I am not a believer in all the preamp hype. Not by any stretch. In the grand scheme of things, they are not nearly as important as they are made out to be on internet forums. However, better pre's do help. Especially if you have good mics, converters, and a good room (as well a good source). IMHO the RNP beat out every cheap pre I have ever heard. It wasn't until a got a MUCH more expensive "clean" pre that I sold it. It isn't perfect, but if you can't make a great recording with it, you are doing something wrong. Not everybody needs a pre as good as the RNP. Most on this site wouldn't probably even hear the difference thru their crappy converters in an untreated room after they had their guitar amp cranked to 11 for the past three hours. This makes "upgrading" to an ART pre even that much more pointless though.
Nick's work is ready for a better pre if you ask me.............