Yes DSP speakers are best bang for the buck upgrade wise and I see the DSP5200HC limiting your systems potential for both Movies and Trifield.
A DSP7200HC will be your biggest upgrade apart from upgrading DSP7000 to DSP8k's.

1. DSP5200HC -> DSP7200HC
2. DSP7000 -> DSP8000
3. 861v3 -> 861v6

After the full DSP Speaker upgrade (DSP7200HC and DSP8000) you can crown the system with a second hand 861v6. That would give you the best bang for the buck system on every step of the way. Do it piece by piece. Go for the weakest link which now is your DSP5200HC.

DSP8000SE, DSP7200SEHC, DSP5200SE sides, DSP7200SE rears, 861v8, 210, Sim2 Ultranero 4, Stewart Cinecurve 2.35:1, XEIT CM-5E Anamorphic lens, Dune HD Duo Cinema 8K and Wireworld Platinum 48G HDMI -> UHD722 -> Shunyata Omega Ethernet. Shunyata/Furutech power-cables/filters. SR Master Fuse@861v8. Uptone Etherregen with 10MHz OCXO clock.