I wouldn't rock the boat this close to your test - you're potentially only going to see him for another six lessons if you maintain one a week. If him being quiet bothered you that much you should have changed earlier I think.
Are you taking the test in your instructor's car? If nothing else, a new instructor may have a different model which will throw you on test day. It's better to stick with what you've built the experience up with.
I had lots of instructors because I moved a lot before I took my test and I can honestly say they're all different. It IS up to personal preference what you prefer but I don't think you can demand he tell you stuff about himself. Him being quiet might also have helped you concentrate better while you learned the ropes.
Anywhoo - good luck for your test! You won't have to see him again after six weeks if things go well