While I haven't played the game myself, I have been watching my brother play Dragon Quest 8 quite a bit lately, so I suppose I might as well write a bit about it. Namely, I want to talk about the casino minigames found in Dragon Quest 8.
Casino minigames are reasonably common in videogames, though most of the time they are not as elaborate as the minigames seen in Dragon Quest 8. For the most part, they work well as (hopefully) entertaining diversions from the main plot that can be very rewarding. In many ways, DQ8's casino's are a good implementation of the idea. The casino doesn't use normal currency, but instead uses special tokens that you can exchange for special prizes. This means that, in addition to being an alternate source of income to defeating hundreds of monsters, the casino serves as a place to get special items that are hard or impossible to find anywhere else in the game, so the player actually has a reason to spend time playing the casino minigames. Also, the Dragon Quest 8 casinos let you successfully start earning tokens even with a modest initial investment, so you don't need to wait until late in the game to play. Of course, while I haven't seen the main casino in Baccarat yet, the casino games introduced so far in the game have a noticeable flaw: they can be very tedious.
Unlike in real world casinos, you can't ever really lose in a videogame casino minigame. If you happen to take a loss, you can always reset and try again. Any casino minigame, no matter the game's odds of winning, will eventually earn a net profit for the player, given enough saves and restarts. As such, there is no particular point to stacking the odds against the player like real casinos do, since all it does is make the player lose and retry more, and make the process fairly tiresome and less fun. Instead, I think casino minigames should always put the odds in the player's favor, so that the player can enjoy the thrill of winning without having to waste time by losing and retrying dozens of times before getting even a minor win. In fact, even if the odds are in the player's favor, so long as they are not high enough for the player to notice the odds and take advantage of them, they are not good enough.
One of the best casino minigames I have ever seen in a videogame is the Poker/High-Low minigame from Xenosaga Episode 1. If you know how to properly take advantage of that minigame, it becomes an easy and fast way to make money in a game that otherwise gives you very little (I suppose you can also do the Gnosis/gemstone transformation trick, but that is a different subject), simply because it can give you insanely high odds. It is a casino minigame where the chance of winning is high enough that you can expect to win a few times every time you sit down to play it, so you never feel like your time is being wasted by the minigame. Another good casino minigame that is comparable can be seen in the Pokemon Diamond and Pearl games, though I don't think the odds are quite as high as they are in Xenosaga.
Meanwhile, my experience with the casino in Dragon Quest 8 has been somewhat lackluster. The odds are bad enough in DQ8's bingo that it can take a few hours of play to make even modest gains, which can include several resets. What is more, the fairly low cap on how much you can bet means that it can take a lot more effort than necessary to earn decent things. While this may change once the larger Baccarat casino is opened up, it seems like it would be poor game design to make the less fun minigames available long before the fun ones.