Prefer the silicon as do those with aircraft.
Have heard most of the problems that some have encountered, usually a description of different pedal feel is a complaint.
One thing to keep in mind is compatibility with seal types.
Most rubber o-rings a a buna-based rubber. Problems can start if the o-rings have a significant amount of silicone in their construction.
Silicone fluid will soften rubber with significant silicone in its construction.
Been a big fan of Viton o-rings in any hydraulic application I'm involved with, the price slightly higher but no issue plus they last far longer and re more durable.
The paint being safer was the reason i started using it.