Yes, I know the lady who teaches the course (a freind of my ex) I was on the course a good few years ago and did find it beneficial however, it's like learning any language, 1 hour a week really isn't enough but if you just want to learn a few phrases then the course is fine.
On the subject of class sizes the funniest thing happened. Our class was a group of around 20 with most of them being woman who had fallen in love with 'Mustafa' or 'Mehmet' the wonderful waiter she had met whilst on holiday. As the course went on through the weeks it ended up with around 6 of us. Mustafa and Mehmet must have upset these young ladies, I can't think how!.
The Brasshouse is just off Broad St, so parking can be a bit pricey.
Is it worth it? Well, that depends on how much you want to learn. I must admit its a great way to meet people who have the same interest at heart. To really benefit from the course you need to set yourself a few hours a week to run through your Turkish vocabulary.
If you need any leaflets or anything Dido. Let me know as I don't mind nipping around there for you and I can post any info that I think you may find of interest.