I've been to The jazz Cafe many times and I am seeing Chuck Berry there next week. I think it's a great venue that is small and intimate with a decent view from almost anywhere downstairs.
But be warned, this only applies to the standing area. Should you wish to book a seated place upstairs, tickets cost about £10 more, you have to eat so will have to pay extra for a meal, and unless you get a balcony seat, you will not be able to see the stage.
But go along to any event that takes your fancy, stand up with the rest of us, and have a great time.

I agree with Ken re this venue. I've seen Richie Havens in Glasgow several times but, earlier this year, came down to introduce some local friends to both the artist and the venue. They all loved both and two of them have become 'regulars'.
Last year I came down  and treated another friend to the upstairs meal. The food was 'OK' but not really worth the extra altho' we were lucky and got a balcony table. However, on the whole I do prefer the more intimate atmosphere of the downstairs. One further plus is that there was a mix of people of all ages. In our party the youngest was 25 and the oldest remembered Richie the first time round!