It's your amp (someone on Agon told me that once when I was complaining about my speakers and I did not believe them; turns out they were right, though it cost me thousands to learn that lesson!).
I bought a pair of Dali 400s after owning a pair of Paradigm Studio 100 v3s. I like both of them, but they are balanced differently, and by most measures the Dalis really are quite a step up. If you're after maximum slam and a heavy balance in the lower mids, then I suspect you might prefer the Paradigms. But for resolution and soundstage, the Dalis really walk away from the Paradigms.
As mentioned, both speakers reflect the character of the downstream gear, but the Dalis do so more than any other speaker I have owned (cables too), so I suspect your issues with these lies primarily in your amplifier and source. I bet that if you find the right pieces, you will experience the improvement you're after. These are excellent speakers, although surely not to everyone's taste (nothing is).
In other recent threads on these speakers, Dave (Dcstep) expresses his opinion that they worked best for him with gobs of power. My experience has been different, as I prefer them much more with a medium powered tube amp (Rogue Tempest II) than I did with a high power amp (MF A5).
I do agree with Dave, though, that these speakers reproduce well what they are given. If you can audition a high quality amp, I would not be surprised if you change your mind about them.
