I prefer metal brightline finders for most occasions. Sports finders when action is more the thing.
There are many companies that have made good ones. CV metal are my favorite, I like their plastic ones too, but their metal just look VERY GOOD. I have a sneaking suspicion that they make most of the new ones for everyone for the last ten years.
Nikon, Canon, Leica and even the off brand (by today's standards), long as they are brightline the are great.
With regards to shaking, I used to worry, but I've gotten over it. Framing a RF is not as exact a science as say an SLR is. Odds are if it's loose enough to impact it shot then the glass will fall out I about 10 minutes.
B2(;->