Training is a personal issue. Have taken ARC every year for the past 5 years, get better every time - also took the Total Control course by Lee Parks. Eventually want to take a civilian police motorcycle course - 2 weeks of ride like a bike cop - here's the link https://advancedridertraining.com/
. As has been mentioned, learn something new every time, you're at your best just after the course and go downhill afterwards due to just riding and not as diligent in practicing. Practicing is your friend. I think the money spent on an ARC is well spent and better value for your money than insurance, but insurance is mandatory, training is not. Want to take an offroad course, and now that I have the Vee, will be looking into it.
It also depends on your bike. Nice to go on an ARC where the instructors teach on the same bike. Did that with my '08 1800 Goldwing (since sold). Found an ARC where the lead instructor was one of the top riders at the Goldwing Wing Ding. He also demonstrated everything on the course on his 1800. It was quite impressive to watch. The instructor who was on the 1800 would do a "follow me" near the end of the course and push you until you had had enough. Sort of like the Top Gun movie where the instructors push the new pilots to their limits and beyond. The after course discussions were an eye opener as well. One young fellow on a lighter and less CC of a bike mentioned that he almost quit, but after seeing the 1800 Goldwings go through the course he was determines to do the same.
A benefit from taking these courses is you meet some like minded riders, and have a great time. It's interesting to see how everyone progresses.
Just a few thoughts. Never too old to learn new skills or refresh your old ones. We all develop habits that need tweaking/correction every now and then.
As an aside, the Victoria Police department has changed over to DL1000 Vstroms for its police bikes.