Docks, to answer some of your questions. Deftech has a huge following, but some "elitists" think that the only way to get great sound is to spend a huge amount of money and only higher end speakers will do. So they bash DT without giving them a proper listen. Also many showrooms don't have the proper "rooms" to demo DefTech and their bi-polar design. (either the rooms are treated with acoustic treatement along the whole wall that the speaker sits on, they have the speaker to close to the wall or the room is in a huge "best buy" area with nothing behind it and so the sound gets hindered.
So these elitists say that the speakers were crap when they heard them. It takes a while to get placement correct for bi-polars and no showroom is going to go through that. But when you get the DT home it will sound way better than what you heard in the showroom. The "sub" can be properly adjusted, speakers properly placed and when you mix in Audyysey (or others MCCACC, YPAO...) you get even better results.
As for the difference between the 7000 and the 7001, you just get better bass extension nothing else. The mid range and upper frequencies are the same. But use caution because most here feel that the built in subs in the 7*** series should not be used as typical subwoofers because they drop like a rock below 30Hz, so many set them to small and cross at 40hz, by doing this you get far tighter bass response and the bass doesnt become bloated. So factor in an outboard sub.
Deftech makes fabulous speakers, I had a A/V GTG a few weeks back and one of the attendees has a complete upper end Dynaudio setup and even he was surprised at how well my setup sounded and declared it very high end (especially for what I paid, which was far less than his Dynaudios)
Comparing the 7000 with the other BP line is not fair because the others can use different size mid range drivers which naturally will change the sound, also the sub drivers have different sizes and wattage but if I were you I would have the salesman set all the series to small crossed at 40hz and then demo with your ears and let them be the final judge.