I would go with the towers too as you will get a more seamless bandwidth for stereo music listening. It can be a bit of hit and miss trying to get a perfectly smooth mesh between the speakers and the sub for serious music listening.
The M60TiSe are also a three way design so there's a driver dedicated to the vocal range so expect more detailed voices on the M60TiSe over the M3Tise.
The M60TiSe are no slouch in the stereo imaging department either. With proper positioning, they can disappear sonically very nicely and present you with a very convincing soundstage.
