My transducer from the DSM300 is a P319. Seems to work okay because the DSM300 was the problem. So with the RV212 pair and an analogue transom transducer, I have lots of redundancy.
Would it be worth calling Airmar and speaking with an engineer? They might be able to give guidance on the DTS800 issues and see if they are rectified. The nice thing about the DTS800 for you is the simplicity of installation because it's a retractable insert. No ST50 or ST60 necessary; simple plug 'n play into your STng backbone; plus you get a new and better depth instrument. Good luck in your decisions.
Would it be worth calling Airmar and speaking with an engineer? They might be able to give guidance on the DTS800 issues and see if they are rectified. The nice thing about the DTS800 for you is the simplicity of installation because it's a retractable insert. No ST50 or ST60 necessary; simple plug 'n play into your STng backbone; plus you get a new and better depth instrument. Good luck in your decisions.