The Tide will engage the Wides if you use Neural:X. I was surprised by this and thought something wrong, but the miniDSP DevTeam confirmed what I heard. In a 9.1.6 system, Neural:X engages all of the ear level speakers plus the front heights. My assumption (incorrect) was that Neural:X would skip the wides and engage four of the heights, which is, in fact, how it worked with a different processor that I owned.
The Tide Neural:X implementation starts with the ear level speakers and with channels left, goes to the heights. A 7.1.4 set up will engage all of the heights, a 9.1.6 system engages one pair of heights. This was the behavior I noticed playing back lossy dts quad and dts MAHD music, and a dts MAHD encoded TV show discs. It was very effective. Limiting to the Front Height speakers was fine.
I would not want to pay extra for dts:X pro.
Edit: this applies to the PCM neural:x upmixer also. If material is dts encoded, it is automatic (assuming you have the preference set), if PCM you must select dts (or dolby) with the remote. dts gives more discrete effects vs DSU.