Here's a question: how many of the deckbuilders out there have a Dominion-style card supply? By this I mean a supply that consists of several piles of (usually) identical cards. It seems like most deckbuilders (Thunderstone, Ascension, Star Trek, apparently Lord of the Rings) have a card supply that constantly cycles, which presents two "problems".
First, it means that it's much harder to have a long-term strategy. You have very little control over whether the cards you need will be available to purchase when you [need/can afford] them. I'm a big fan of tactical play and making the most of what's handed to me (Kingdom Builder rules!), but it's best when you can pair that tactical acumen with a coherent strategy.
Second, it makes each play of the game feel more samey. Sure, you may have a big deck with over 50 unique cards, which is a lot of variety. You shuffle the deck, and the order these cards become available makes each game play differently. Perhaps you won't get through the entire deck in most games, so you may never see certain cards in every game. I can name another game that meets all these characteristics: Uno.
The fact that Donald X. games in general (and Dominion in particular) don't include every card in each game is huge. No two games of Uno are ever going to feel as different as a King's Court engine is from a Duke slog. I'd argue that this, not the deckbuilding mechanic, is the defining characteristic of Dominion and the thing that gives the game such incredible staying power. It also makes it easier to make and sell expansions. Imagine if Dominion only had two sets with 100 Kingdom cards per set, but only 1 to 3 copies of each. It'd be a worse game AND wouldn't have made nearly as much money! Yet this is a mechanic that most subsequent deckbuilders chose not to incorporate. Go figure!
I'm not interested in appearing on the podcast but I'll add this for the one who eventually does go on:
My first deckbuilder was actually Ascension, a game I still love (and it's the only other deckbuilder I played). The three main reasons that Dominion sees more table time have nothing to do with variety but:
1. My friends are really put off by the theme in Ascension. "this looks like Magic"
2. Because of the continuously varying supply, the first few games have a lot of card exlaining DURING THE GAME (rather than before the game as is the case with Dominion)
3. Ascension gets worse with more players
First two are obvious, third I'll get to later.
Other than also having the deckbuilding mechanic, the "feel" of the game is different and the games are tough to compare as a result. An analogy:
In football (which is called soccer in some backward countries :p) the players and the coaches have a completely different perspective. The coaches analyze the conditions, their own tools (i.e. player skills) and the tools of the opponents before the game, and decide on a strategy taking into account all this. Once the game is going, their influence on the game is very limited; they are allowed just 3 substitutes, and can give some further instructions to their players. Sometimes bad or good luck happens (lucky goals, injuries, bookings, etc.) and they have to adjust accordingly. But if any really major adjustments are required, there is only so much they can do.
For the players on the other hand, they go in with the instructions of the coach (a general strategy), but once the game gets going, for them it is more of a moment-by-moment game; stuff happens, they have to respond, to which the opponent responds, etc. A small error; an unlucky referee call; fouls; getting under the opponent's skin - that is the game for the players.
I'd say Dominion is more similar to what the coach experiences, while Ascension is more similar to what the players experience.
In Dominion, you look at the board, decide what to do, and do it. Even though you do have to take into account what the opponent might do and/or does, often when you have to seriously adjust, either due to bad draws or due to the opponent choosing a strategy you didn't identify earlier or due to just having picked a bad strategy, it's an uphill battle. Also, there is very little you can do to stop your opponent from doing their thing - you have attacks, but which attacks are available was known before the game even started; card denial is limited to winning the split; sometimes you can flexibly open preparing for either slog or rush; and then you have Duchy dancing and three-pile-control.
In Ascension, you play more on a turn by turn basis - you grind the margins, each turn you try to find the balance between scoring more points than your opponent, making your opponent score less than you on his next turn (card denial is HUGELY important), and cutting your losses to set yourself up for more point scoring later (either gambling on favourable center row draws or buying cards that allow you to control the center row). Go with the flow, continuously adjust to the current conditions and to the opponent.
Both are a different beast, I like both.
Then I return to the >2 players problem of Ascension:
Inherently, each turn you're trying to do better than the player who went before you, and you're trying to set things up so things suck for the player after you. In two player games, the player before and after you is the very same player, so it's all fine and dandy. With more than two, however, you respond to one player, while making a third player respond to you. Your influence on any other players is negligible. This means that the player who sits behind the worst player has a distinct advantage. Which sucks.
For 4 (or 6) player games they did come up with a fix: TEAM GAMES! In this you play in player order A1-B1-A2-B2, and add the scores for team A and team B at the end of the game (but each player has a separate deck during the game!). You can choose to pay extra to send the card you bought to your team mates deck rather than your own. This sounds awesome, but since everybody I play with wants to play Dominion, I haven't been in the position to try it. Oh well. It's not like I'm not having fun with Dominion. My 5 province - 2 Duchy HoP megaturn of two days ago certainly was enjoyable...