As with Aqua Vitae, I played a couple of test games against AIs to see how this card played. As a reminder:
Retort
$4P - Action
+3 Cards
+1 Action
Discard a card. If it is a Potion, +1 Action.
I played two games, one with no Villages where I loaded up on terminals and used Retort chains to draw Potions (I bought 3 total) to discard. My terminals were Swindlers, Horse Traderses, and I think a Courtyard or two, and probably something else I'm forgetting. Anyway, I wound up buying too many, as I did wind up with terminal clashes a bit more often than I'd have liked. However, the Retorts were pretty good at giving me extra Actions when I had them; the card draw and the extra Potions generally meant that I had them to discard when necessary, though not always.
When I did not have a Potion to discard, I ALWAYS had something else I wouldn't miss -- Estates, usually. Possibly a dead terminal once or twice, but basically just Estates, and then Provinces once I started buying those.
On my second game, I tried not bothering with multiple terminals at all. I bought a kicker (Council Room, for the +Buy), two Potions total, and massed Retorts for a drawing engine. Otherwise, I just bought Treasure and ultimately Provinces (once I only had $5 and so bought a Jester). I was expecting the drawing engine to be too easy to set up, since the net +2 Cards with filtering is way better than Alchemist's flat +2 Cards. But it was fine -- reasonably strong, but not too much at all. I think this was because the Retorts were too expensive to mass, and of course they don't set themselves up for your next turn like Alchemists do.
So, so far, I am happy with this one and think it's pretty much spot-on.