Oh boy, reviewing Payday 2. What's there to say?
It's the essence of 'good enough' turned into a game. It does not have many noticable good points nor many obviously noticable flaws.
It's an fps game with decent graphics, decent guns, and decent action. You can sneak missions or just go in and shoot everything up. Most objectives are fairly simple 'loot x and move the bags to extraction point y', which earned it a nickname of 'Bag moving simulator'. Luckily, most later missions move away from 'just move loads of bags' to more interesting missions, but the majority of missions are still fairly simple looting missions.
Loot that you can use mainly to buy more guns, and at times a customised mask. Aside from that, your money is essentially just a number that goes up after you win a mission. You should not have any problem with money unless you are actively avoiding the higher difficulty missions(Which are not all that tough except on Deathwish difficulty). Most of the higher difficulties are only just adding more health or damage to the cops, or adding more specials like tasers and riot shields.
The game as a whole feels unfinished, as though they reached the halfway point in making it and then decided 'good enough, polish it a bit and start selling'. Considering the DLC they've put out, I highly doubt they had any actual plans past this first half, or maybe they just cancelled whatever they had, I can't say it's showing any sort of long term planning.
Being a 4-player team based game, of course you are best off playing with friends. Teamwork is essential for some of the harder missions and difficulties. You will generally find it much more enjoyable if you play with people you know, as it is at its core about a group of four friends working together to pull of heists.
In the end, it's an alright game, with DLC piled upon DLC with DLC attached, most of which are extra guns or cosmetic changes, with a few of them being new heists to do. It's worth noting that only one in four players needs the heist DLC, and the rest can join the host without owning it.
In the end, Payday 2 is alright, it does just enough to be considered good and playable but not much past that. If you have friends to play with, pick it up when it's on sale, have yourselves a good time and then shelve it again - There isn't much replay value past achievements and trying to just bring your money number as high as possible. No endgame, no safehouse customisation, and no way to really spend your ingame money, just more of the same heists you've already done.