The skeleton structure of a person is strongly connected to his strength, muscle size, speed...etc. In bodybuilding it's hard to say what's better - small joints or big joints. Why?
If a person has big bones this usually means that he/she will have bigger muscles compared to a thin/fragile individual. However the person with the larger bone structure will also have bigger waist and since bodybuilding is based on illusion the thin guy may end up looking much better than his/her rival. As far as men are concerned any bodybuilder/fitness enthusiast with under 7 inches wrist has small bone structure. On the other hand anybody with 7.5-8+ inches wrist has large skeleton structure.
A person with 6' inches wrist and insane genetics would be able to have about 16+ inches arms at a decent (below 12%) BF* At the same time a big boned trainee with 8 inches wrist will have about 18 inches arms. Who is bigger? Well, technically the guy with 18 inches arms. However we all know that in bodybuilding the winner is not the guy with the biggest measurement and the guy with 16 inches arms may actually win. What about strength?
When it comes to strength the guy with big joints has full advantage. Actually I can't think of a single advantage small bones offer when you are a powerlifter. The goal is to push the most weight and having stronger and bigger skeleton gives you an advantage right from the start. A lot of guys with small wrists have trouble benching. Also small hips can be a problem for squats. The only strength exercise than does not give a fuck about bone size is the deadlift. The reason for that is quite simple - during the deadlift you are not supporting the weight with your limbs but you are rather pulling it towards your entire body.
Ed Coan, the most famous powerlifter, has 8 inches wrist while some of the most aesthetic bodybuilders out there like Serge Nubret, Vince Taylor and Flex Wheeler have small - 6-6.5 inches wrists.
Ed Coan - 8 inches wrist
Vince Taylor (on the right) has really small wrist which gave teh illusion his arms were bigger.
"all the top pros i've met have tiny joints. when i met Vince, our arms look close to the same size. but if you saw a pic of me onstage alone, and a pic of Vince on stage alone, you would guess his arms 3 inches bigger at least.
my wrist is probably 1.5 inches bigger than his, and thats why i was never a great bodybuilder."
-hazbin (member of Getbig.com and also the guy on the left)
It's not about height
A lot of people such as Lee Priest believe that the taller guy should have bigger measurements than the short one. It's not true. It's about bone thickness and size. The height of a person does not determine his/her bone size - only length. In other words just because a guy like the 5'4 inches tall Lee Priest has 20 inches (obviously he has been abusing drugs since his creation) it does not mean that a guy who is 5'10 should have 25 inches. No. The measurements of a person are determined obviously by his level of development but also by his bone size. A person who is 6'1 tall with 20 inches arms has 50+ pounds of muscle more than a 5'4 guy with the same arm size.
So, Lee Priest can fuck off and go heal his Napoleon complex. Truth be told naturally he will be 140 lbs top at his height. He competes at 200lbs. Case closed.
Conclusion: Small joints may be great for bodybuilding while huge joints work better for Olympic weightlifting and powerlifting. In all cases be happy with what you got.