Volvo IPS improvements

I have upgraded from a 2002 Tiara 38 open with Cummins straight shaft to a 2017 Riviera 445 SUV with IPS 600. I am fortunate to have a service yard very familiar with the Volvo-Penta's. We have used the boat for 2 years running around Long island Sound. I was pretty confident with the Tiara and Cummins and bow thruster in tight spots, the Riviera does not have a bow thruster, but the joystick/IPS configuration at low rpm's does not need a bow thruster and is very good at tight spots at low RPM's. I also like the result of the engine configuration being placed under the cockpit instead of under the helm. Quieter and opens up the berthing cabin below. The maintenance costs so far have not been an issue, but we are at under 300 hours. I am very cautious with draft, but I also was that way with outboards, and the Tiara.

I own one of the first if not the first Sportfish's with IPS.
I have 3200 hours not without growing pains.
Both of my pods have been replaced with remanufactured drives to F specifications.
I made the decision years ago to stay the course and accept drive replacement as maintenance. The various replacement of the computer modules is a pain but all boats are going to computers.
I had the same boat with Cat 3126's, no joy of ownership with those motors.
She cruised at 23 knots and burned 34 GPH.
The IPS does 29 knots burning 30 GPH!
I am frustrated that Volvo Penta will not be building the D6 435 HP any longer, not sure what I will do when I need a motor.

I was under the impression that you could just use the new D6 440 or 480 but I could be wrong. I hope you can for your sake. It’s always great to hear positive feedback from a long time ips owner.

I recently purchased a 2009 52 Ovation (Silverton) with triple D6 435 ips 600s. The engines have about 1300 hours on them. I have become quite familiar with the engines and drives over the last year but I am always looking to learn from others with experience. My main question is broad but important. What type of regular care/maintenance should I do on the IPS drives? I know what Volvo says in the manual but I am looking for any tips from people who have real world experience like you do. My biggest concern is having water intrude into the drive (through a bad seal or something). Any input is greatly appreciated!