personally i have joby slr zoom that does the good work and worth the buy. it is very sturdy.

so far it served me well for my traveling usage to replace the huge standard tripod.

however talking about flexibility and durability, it really depends on how one uses it. the joints still durable up til now, but im not a daily user.

if you're a frequent & heavy user, it is definitely gonna have some wear and tear on some parts. depending on how often you use to bend the joints.

but of course you have to make sure you got the authentic product from joby, not those china imitation product. those comes cheaper than joby srp sure wont last any longer than the original.