Very nice home. As I said earlier, the biggest issue with your sound is that the DefTechs are ill suited to your room from their radiation pattern. They radiate over a very broad area as they are nearly omnidirectional hence minimal directivity of the sound. Thus sound bounces around the room and creates the sound that you don't like. Furthermore, you have them placed far too close to the wall.

Near field line arrays would help alleviate much of your room issues plus a monopolar speaker will allow closer placement near the wall. To get the bass that you desire in your room you'll need two subwoofers. I would suggest that you use no center channel, i.e., a phantom center channel. All surround processors allow for a phantom setting and with the front speakers as close you have the DefTechs, you will have more than adequate fill with the arrays. Ideally, for a 5.1 set-up you could use a set of line arrays for the rear surrounds. Line arrays for the rears would better match the intensity and sensitivity of the front arrays. Bottom line: 2 pairs of arrays and two subs would be what I suggest.

A set of near field line arrays in your room would yield virtually constant sound intensity throughout the room with no hot spots even on the side of the room with the front arrays. Near field radiation falls off at half the rate of a point source and the wide image will enable good sound to be heard throughout the room.

The Linus 2 and 3 arrays differ from each other enough (drivers, components, and cabinet) that I would not suggest a stepping stone approach from the 2 version to the 3. What you might do is to build a set of Linus 3 arrays and subs for the front speakers and try that out in your room for a while and then you can choose to build another pair later.

Jim