Adam . . .
have had a few other posts, but here's a summary:
1) Love the device. Use it regularly now. My wife and I typically drink 1 glass per night. On these nights, if I am leaving for work the next day, I no longer hesitate to open anything.
2) Have experimented with wines with <10 years on them. For 2 different labels I accessed 1 bottle with Coravin and had a identical "sibling" bottle for later comparison. For 1 label, I did a comparison at 1 month and another bottle I did a comparison at 2.5 months. Absolutely no difference. The coravin perfectly preserved the wine
--> A recent WS "test" of the coravin posted slightly different results. But, interestingly in their review, they said some tasters preferred the Coravin accessed wine
3) Tested this on a 1961 Figeac (ignore my score on that wine as compared to my qual remarks please!). The Coravin provided a great way to access the wine. However, the cork was too brittle to retain a closure after being accessed.
Overall, great device for wines with natural corks that are still resilient and in good shape. There's no universal wine age cutoff for using this device, but my guess is that once you go beyond 20 years and cork integrity starts to wane a little you will want to be extra careful. If the cork shows any signs of not holding up against a typical waiter's cork sscrew, I would not expect this wine to retain a perfect closure after being accessed by the Coravin
RE: COST: With regular usage (~1 use per week; we only use this is we can't finish a bottle in 2 days), we go through 1 canister of Argon gas every 4-6 weeks. Canister longevity totally depends on how much wine you're removing from the bottle. This has been incredibly difficult to estimate, but based on 3 months of usage, I am guessing that the canister is good for removal of 60-70 ounces of liquid (slightly under what is suggested by Coravin - 75 ounces)