I worked for OCS on and off for about 2 and a half years. The worst part about the job was the amount of hours you were travelling to the different jobs around the country and not being paid for.
The hours were unpredictable, some weeks you are very busy, other times (especially around Christmas), there is little to no work on offer.
The work itself wasn't the worst when you actually got on location. It was fairly straightforward and you knew where you stood. Job times ranged from 2 hours to 12 depending on the situation.
This job is ideal for students looking for a little extra income every month, or if you're unemployed and just need to make ends meet whilst you find something that will actually be properly worth your time.
The people and supervisors I worked with were on the whole decent people, you end up working with the same people a lot so you get to know them. The people you meet and work with are without doubt the best part of this role.
Overall, if you can, avoid it, being out of the house for 17 hours and being paid £50 isn't fun. There are plenty of other jobs willing to pay the same in your local areas.