Start with the pros: huge variety of laboratory projects available in 3rd year. Great labs in year 2 and 3 (albeit poorly scheduled).
I'm not familiar how it compares to other Russel group unis. Most lecturers are good but you get a few who are clearly focused on their research and don't care to teach.
Here's an example that really annoyed me in the stereoselective synthesis module in 3rd year: professor will put an MCQ problem on the board during a lecture. Let's say there are 5 possible answers. Each answer will literally have 20% of the votes and the prof seems to take some pride in that. Doing well in that module requires extra work outside the provided lecture slides, and lecture content - its simply not worth it for most students wishing to optimize their grade (huge time investment for only 5 credits-worth). This is a huge shame especially if you're interested in organic synthesis.
The net result is that UCL chemistry department awards the lowest proportion of first's and 2:1s out of every department at UCL (I checked with their published data last year).
In terms of finding a job, I am starting as a technician in an analytical development lab. Used no uni support except references for this. In fact, if you want to do industry science afterwards then don't go to UCL, go somewhere that offers a placement year. It is invaluable.