I used to go gaga over this card. And yes, this was even when we were NOT using it to gain Duchies (it seems more than one group has missed that you can only gain
ACTION cards that cost up to $5). Chalk this up as another card that's really not THAT good. A card that costs Potion no less
Does work to buff up Vineyards. Not uncommon to have Vineyards worth 6 to 9 pts per due to this.
Which $5 cards is it best with?
I'd say it'd be nice to get Great Halls with this, but I'd like to think they'll be gone by the time you can get that many, if any at all with a Uni.
Cards you'd like to have a lot of. Already covered by
ced... Minoin, Lab, Highway. I'd also add Lost City and Treasury to the mix.
When is it a trap?
Otherwise, to get $5 cards, they should be easier and quicker to get without Uni., unless there are cards that bog decks down (like Militia).
How awesome is the combo with Watchtower?
Pretty. Play a Uni., top deck a $5 or useful action card, and then you'll be guaranteed to get it AND have the action to play that one action card.