Ya actually. My dads 34' sea ray has em....we've tried to fix them many times. Finally just gave up and keep adding fluid. My friends 30' Center console has them, he loved them. Had it out two weeks ago and both cylinders were frozen. My uncle in-law I guess you'd call him, has them on his 23' center console and just had to replace the hyd motor last season, season before that one cylinder busted rendering the whole system useless and contaminated.
Now on the other hand (won't name off all the boats I know) The lencos have been installed and completely trouble free for years, some trailered, some docked.
So yes, based on my experiences with bennetts I can say they are prone to leaks and failures.
This however is my opinion....I could be wrong