"Aren't too big" means the RS6 AV is off your list.
You mentioned in another post you have around £1600 to spend, which means you don't have to 'settle' for the 3005SEs, so they're outta here.
That leaves the MT-30 and the RS1s. The RS1s will undoubtedly give a bigger (and better) sound, but of course you then have to deal with the not so small matter of actually living with fairly chunky speakers and stands around your room. If you've got the space then great, if not then you might need to look elsewhere.
The MT-30 system is a great sounding system (I know, I have one), and has discrete installation on its side too. OK, you're gonna be losing something when compared to traditional speakers, I guess the question is what are you prepared to do?
One thing that hasn't been mentioned is perhaps a slight 'mix 'n' match' approach. You could for example use a pair of RS1s on stands for your front pair but use some of the M.A Radius range for the surrounds and the centre. Likewise, you could run a pair of B&W 685s for your front pair and then use the M1 satellites for the centre and surrounds.
If you've got space under your TV, you could use the matching centre for the B&W 685s (Or the M.A RS1s......Sorry, don't know the model designations) and use the style system speakers purely for the surround channels.
I would advise auditioning all of your shortlisted packages. You may find that the style systems packages don't lose as much as you think, compared to their traditional cousins.