I'm running the first setup you mentioned minus the ADP-590 for surrounds, (I'm currently 3.1 till I get the money together for 5.1).
I have the mains bi-amped off of my VSX-94TXH, and a Velodyne DD-15 sub. I definently felt that the sub was a welcomed addition, it blends seamlessly with the Paradigm's.
Regarding what runninkyle17 said, if you don't have a sub, or are not planning to get one for some time then the deftech's are definently the way to go. A very good friend of mine has the 7004's plugged into a Bryston 4B SST and it was a jaw dropping experience for me. I haven't heard his system in almost a year now, and not since I've had the Studio's, so I couldn't tell you the difference anymore. All I know is that I get a jaw dropping experience now anyways on a daily basis.
I've heard many people say the Veristas' are the cats-@ss, but I've never heard them to give an opinion on it. I will say this however, there are some things on the spec sheets that lead me to believe that the Veristas aren't so hot as the hype goes (but again, I've never heard so I'm ignorant on this matter). Some examples;
As per both manufacturer's listed specs:
Paradigm Studio 100 v.4
Frequency Response - [±2 dB from 44 Hz - 22 kHz]
Sensitivity - [91 / 88 dB]
Energy Verista V2.3i
Frequency Response -[±3 dB from 35 Hz - 20 kHz]
Sensitivity - [90 / 87 dB]
The differences are minor here but (in my opinion) in favor of the Studio's. The Studio 100's also have 5 drivers, whereas the Veristas V2.3i have 4 (not a selling point, just mentioning it).
An interesting difference on the spec sheets, (hopefully someone here can clear this up for me), is the listed weights of these speakers. Paradigm specifies the weight of a pair at 162lbs, whereas Energy doesn't specify if its a pair or just one, they just say 68lbs for shipping weight. My assumption is that Energy is just listing the weight of one speaker, so if thats the case then the pair would weigh 136lbs. A difference of 26lbs, or 13lbs a speaker. The Studio's have an extra Bass driver and a larger cabinet. It would seem to me then that the Veristas is probably the heavier/sturdier cabinet compared to the Studio 100's.
Anyways, I've devled too far into the Paradigm fanboyism, so all I'm going to say is that like you mentioned before, hearing is believing. Go out and compare'em, and let us know what you personally think. Either way, you've picked two great speaker systems to have for options.