so far...excellent....i own four fifty gallon of the thinner walled version...w the screw top cap and rubber gasket..i sometimes have difficulty putting the cover on one particular barrel but consider that a minor issue and have heard that they changed the design since anyways
now back to the good points one of which was cost....my first vintage using these was the 2008 and each have the variable capacity floating skin...which in my mind is over priced but highly effective...i did not use any argon and had no bacteria issues at all when the tank was not filled...
i currently have my 09's in them and they are doing well
cleaning is breeze......you CANNOT say that enough
aging...well i aged some like wine side by side w glass..and for these YOUNG wines...the flex tank wine at the same stage needs less decanting than that aged in glass..i attribute that to microxygenation...glass of course does not give you that and you can turn on a dime as far as your oak choice..and lets face it, that ability makes your tanks more flexible..what if you come to a variety that you would like to use fr oak on..and you only have an american barrel staring at you?
they come w a screw type insert into that same top lid i mentioned previous...dont buy there air locks...its not up to my standards...instead pop out the inner piece of plastic and you will see that that is threaded...go to home depot and get a threaded insert w a smooth fitting at the top to receive your rubber bung and water airlock....if you dont know what i mean, let me know i will take a picture for you
improvements you could make immediately from my experience are as follows
put in a drain and or at the least a microvalve sampler....i did not do that and thus have to open the tank from the top to wine thief a sample and cleaning for me means tipping the tank over..not a big deal until i am in my sixties
next, i would consider using spirals or staves....i did feel that i had to UP my oak chip and cube amounts because they settle to the bottom....either go w a bigger oak substitute or as i plan on doing..suspend the cubes or chips in a mesh bag
side note..for a thicker walled flex tank, i would suggest some splash racking
another side not...none of what i am saying discounts the great value of a good oak barrel...i think an oak barrel has a place in the mix ...you will NEVER get the visual beauty of an oak barrel in a flex tank or stainless or glass.....you will get the cleaning hassles and leaks of course and a barrel that devalues over time...
so to me you want a barrel only for two reasons...beauty and here is the big one...if you can find one that without a doubt has a flavor profile that you cannot duplicate without THAT barrel
gotta run...hope i didnt forget anything...ask if you have other questions