One of the best kart racers you'll find, though it definitely has it's share of flaws. I personally consider this the 3rd best kart racer behind Double Dash and 8DX, mainly due to the problems that exist.
tl;dr Great, but janky, kart racing game that is absolutely worth it, especially if you can grab it on sale (I recommend the Deluxe edition but the base game is fine, too). The game will live for at least another year as of this post, potentially more depending on future sale numbers. Highly recommend if you're looking to have some racing fun. It even has a Demo so you can get a basic feel for it.
I'll talk about the cons first.
Cons:
1. Gadget balance is a pretty big issue. SEGA is trying to solve the problem, but it does seem to take a bit too long to solve it at times. It took many months to fix the UC4 problem and when they did they introduced a new problem. That problem was then band-aid fixed, though it's still far and above the best build. In terms of actually enjoying the game it's not as bad as UC4 but if you don't use it you are still at a pretty big disadvantage. There's really only one other build that can keep up with it. My point being that once you hit the higher ranks lobbies the fun kind of gets sucked away depending on what type of game you were looking to play. Some people have fun Snaking, others like myself snaked back when MKDS was a thing and quite frankly I've had my fill of it. With all this said, I've hit Emerald in every LC but the 1st and only one of those times was I forced to go meta to grab it. I would also like to say that my problem isn't something being meta but how big the gap is between it and everything else. Something being "the best" is perfectly fine. Something being "the best but without real competition" is where the problem arises.
2. Jank and a decent amount of it. It's usually not "I'm going to quit this game" amount of jank, though, but it can be annoying. The biggest issue, however, is when Festivals come around. Playing as a premade will pretty guarantee that you disconnect many times in a night. This seems to only occur when playing Festivals, but those are the most fun and active parts of the game so it's a pretty big deal. No idea if they will ever solve this problem.
3. Items can feel way too powerful or useless. There are gadgets that can solve this, but with the current meta builds those gadgets aren't viable enough to win consistently. There are also some items that desync A LOT, like the Green Glove, which can sometimes hit up to 3 people with 1. The Slicer is also a weapon that is more like a crab claw dragging your opponent back into the crab bucket.
4. SEGA had the smart idea to put a lot of the good looking karts in the Accel type. The problem is this type is TERRIBLE. It's been almost a year and accel is still far and away the worst kart type, really hoping they can fix it.
5. Voiceless DLC. Kind of disappointed that pretty much all of the DLC is voiceless, with some exception to Miku. I'm also fine with Pac-Man and Megaman not having a voice since they didn't originally have one. They rest should have been voiced, though. Maybe it cost too much, not sure since I know very little about how much a couple of voicelines from, let's say, Spongebob's VA would cost. I don't care as much as others, but it is a con worth mentioning. There are mods that "fix" this but I honestly think those mods are low quality and don't recommend them. Just a personal preference, though, feel free to try it out yourself.
6. The tracks are mostly good. I say mostly because SEGA decided some tracks should have a huge shortcut for no reason. It's a shame because most of those tracks are good but ruined by it. It's not the end of the world and you can play around it but it's sad to see. Hoping SEGA stops doing this.
Pros:
1. Controls feel great and the game feels fast. Really love how the game feels.
2. Music is good but you need mod/s, which SEGA is okay with, to fix some mixing problems to make it really good. Otherwise you can just use the Jukebox and select other music included with the game.
3. Outside of the broken gadget build, the gadget system is really fun. There's tons of good gadgets to play how you want to play. Really gives some extra life to the game when people aren't just spamming the same meta build
4. Outside of Accel type karts, you have 4 other types of karts that are able to do well. You can mix and match kart parts and even put in-game decals on them.
5. Graphically it looks great, and runs very well. There are a few graphic mods you can try out to make the game look even better. SEGA has given the okay for mods that don't affect gameplay which is a fun plus.
I bought the Deluxe Edition on release for about $75, and I don't really regret it. I didn't even intend on getting it until I played MKW and watched Nintendo make an okay game worse with updates. My MKW has been gathering dust since I got this game. I've been playing Mario Kart since Super Mario Kart on the SNES and never thought it would lose to a Sonic racing game but imo this game runs laps on MKW even with all the jank.
