I'd say yes, and if the right players played I'd go.
If you say no to a testimonial for Lee, I think you need to do away with them altogether.
If the rule is that you play for ten years and you get a testimonial, that should be the rule. If the rule is that you play for ten years and if people like you then you can have a testimonial, then you open a can of worms.
I've never been interested in what Lee's done off the pitch (except when it's been funny) and he's had a good career with us, think of some of the best moments of the last ten years, and you'll find that Lee was there for most of them, regardless of whether he's a dick.
It would need to be for charity though, I think the days of footballers feathering their own nests with testimonials are long gone.