I think Artest has been (and arguably still is) rather immature in his behaviour, but one thing that I personally feel about him is that he gives guys respect where it is due. If they were on the same team at the start of the season Artest would probably still ball hog quite a bit, but if say he joined the team after seeing how good Evans can be, I believe that he would learn to defer to Evans.
As a presence in the locker room, I don't think Artest is necessarily detrimental or overly beneficial. Kinda like Kobe I would think. He sometimes does and says stuff that distracts the team or isn't really good for team chemistry but he's not like an absolute nut in the locker room (I mean these days). At the same time, he will push his team mates to work hard. While he may not connect so well with Evans like the rest of our young guys do, I think he'd connect more on a lets push ourselves towards getting better in basketball level.
Playing wise is the real problem IMO. Artest's strengths are his ability to post up with his strength and at times command a double team. You wouldn't want him to be a volume outside shooter. This would clog the lane for Evans (unless say you'd just switch Artest and Hawes since Hawes stays outside anyhow...) and Evans wouldn't be able to benefit much off of Artest passing the ball out of the post to the perimeter, since he doesn't have a good jump shot.
Perimeter defence would be very good though.
