how good (or bad) is Dale Jr.?

I've given him the "pass" for a while. I've said it was a poor team at DEI. I've said that he is a really good driver.
Now lets look at it a different way. He is IN the Hendrick stable. ON the Hendrick team. Has info to share from the 24 and 48 team yet he still is looking like an average driver.
Tony Stewart is getting his cars from Hendrick. I doubt he has the info that the 88 team is able to get from the team. Stewart's team is in it's first year together and running like a team that you would expect to have been together a few years. The COT is a drivers car. If you are a great driver it will show in the COT.
I never saw Dale Jr. drive as hard as the last year at the end of the season in the DEI #8 car. if the equipment hadn't broken down time and time again he would have been in the chase. I've not seen that determination since being in the #88. not saying he isn't trying hard but anyone who watched the last few races he had in the #8 car saw a driver that was driven. saw a driver that wanted to prove something to someone. that wanted to make his dad proud.
Is it a lack of self motivation or is he really just a slightly above average driver?

I'm to the point where I think that his crew chief/cousin or whatever he is, needs to go.

His crew chief/cousin is the last person that got him a win.

Thats probably true, but he's cost him a few with decisions as well. It's probably not fair to place all the blame on him but you see teams that have won championships have to change things up, sometimes the parts don't fit together anymore.

IMO Dale Jr. is as good as he is going to be unless they can find a better combination for him with his crew chief. I'm not saying Eury isn't a good crew chief but it isn't the one for Jr. JR needs to have one that will take charge and set the car up to win not one to pacify the driver. There hasn't been too many like that but just look at #48, #24 in his earilier years, and #20 when Stewart and Zippy was together. It can be done but the higher ups with Hendricks organization needs to do their homework better. Their too satified with JR being the most popular driver instead of winning races or even poles. The same can be said for K. Busch while at Hendricks he didn't do as well but when he got with Gibbs the better combination was found.

He had huge shoes to fill and a lot of pressure obviously. I think he's an "okay" driver from what little I've watched, I don't think he'll ever be great. He had a lot to live up to and so far has been a bust.

Hendrick mum on future of Earnhardt's crew chief - NASCAR - Yahoo! Sports

I'm going to bet that Tony jr will not be with Dale jr the next race.

He is just as good as Kyle Petty.