The Class 150 is a classic British DMU from the 1980s, and although the 150/2 variant was released for Train Simulator in 2011, a model of the 150/1 didn't arrive until December 2016. Why DTG still left out the three-car 150/0 and Network Rail Class 950 is anyone's guess.
Dovetail's 150/1 model is awful in its default state (it has recycled and inaccurate sounds combined with ugly washed-out colours on the default liveries). You'll need the Armstrong Powerhouse enhancement pack for this unit in order to make it drivable, but the EP certainly isn't perfect.
I got the idea to make this review after featuring the 150/1 in my recent video on the Marston Vale Line, in which I explained why it should be made as an add-on for Train Sim World 4.
(Footage for this video was recorded on the following routes):
Gospel Oak to Barking
Keighley & Worth Valley Railway
Marsdonshire
Pacific Surfliner - Los Angeles to San Diego
South Wales Mainline
The Kyle Line - Inverness to Kyle of Lochalsh
The Railways of Devon & Cornwall (V11)