so basically all it does is what u saw allready (bank,ec cap, 2 boff slots..all these things can be purchased with zen also)..500 zen each month (applied on the date you became active..so if you signed up 9/18..it will show up 10/18...the extra inventory slots and skill retrain tokens when you level (good if you are leveling alts)...so if you had 500 day veteran bonus rewards before you signed up, it will start to accumulate from there, so on 10/18 you will be 530 day..1 point per day subscribed..
i thought about subscribing but didnt...i signed up then cancelled so i got the first time buyers reward pack..then bought the the ec cap with zen, and the bank slots stayed. for what you are paying each month it is not worth it IMHO..just buy the unlocks with zen and you save money...the only thing you will loose is getting the +1 veteran per day and retrain tokens/inventory unlocks on new characters...your lvl 60 characters WILL retain the upgraded slots when u cancel.
i did the math to get to 800 days of being a subscriber and it well exceeded a lifetime sub. so if you want those veteran perks, the best way to go is to just drop the cash for a lifetime sub, that IS worth it.
this is also very discussed on reddit as well, so check out their opinions too