Read through this thread and make your decision.

 

Unnecessary. You only have to replace when water content is at or near 3%. Takes like 10 secs to measure.

 

It is impossible to prevent brake fluid from absorbing moisture unless you never open the bottle.

 

I may get grief from this. I disagree with the 30k or 3 years change of brake fluid. Yes, maybe in high humidity areas. My car is garage kept. If I start changing parts at 50% of part life, I will be spending a chunk of money. At 30k, why not also change out a good battery, spark plugs, all belts & filters, ignition coil etc?????

 

Are there any downsides from doing it other than the price?

 

Nope. For my cars I see a colour change after 3 years.

 

Yes. Potential damage to bleed screws or introducing air into the brake line if not bleed well.

If you have a hybrid RX, the brakes are so lightly used that the fluid are good for many years