I currently have both speakers and am in the process of deciding which ones to keep. My system consists of a Mark Levinson 27.5 amp, Anthem TLP-1 pre-amp, Denon DVD-900 CD/DVD player, and Monster M-Series biwires. Your mileage may vary but here's what I hear:
Mani-2:
+ better and deeper bass,
+ less colored midrange,
+ superior imaging - the speakers can "disappear" like electrostatics do,
+ smaller,
- harsh and over emphasized highs / sibilance,
- power hungry and inefficient (4ohm, 85dB) - they need a strong, high current amp.
Paradigm Studio 40s:
+ smoother more natural highs
+ very efficient and easy to drive (8ohm, 91dB), should work well with tube amps
+ less expensive
- midrange sounds less natural - a bit glassy at times.
Both are fine speakers. Both are very detailed and will reveal small changes in your system, so the accompanying equipment needs to sound extra good. Both play deeper than their size would have you expect (especially the Mani-2s). Both seem very well constructed and I think they are both very nice looking. Interestingly the Mani-2 "walnut" finish looks identical to the 40's "rosenut" finish.