Rather awful.
The opening few scenes of '198 Grand' are actually, relatively, alright - I felt amused, not because it's anything great but it was more entertaining that I thought it would be. However, that very quickly wore off unfortunately. The longer it went on, the more I was wishing for the end.
There are way too many characters in this, a lot of them are cliché drug-taking, innuendo-filled, gun-wielding London gangsters that you've seen countless times before in these low-budget films. Some, e.g. the main three guys, are minorly funny - the trio do actually work OK together. The ending is underwhelming, even if the outcome is (given the alternatives) a positive one.
I have incredibly seen worse, this gets a mark above the bottom due to its (admittedly poor) comedic side that stops it taking itself too seriously at the very least.