Hmmm... OK but first off you should know that I use roundwounds on everything (I know, it's heresy on the 4005!)...
The 4005 is by far the most comfortable to play being that the neck is so thin and the body is so light. I find that the bridge pickup is WAY thin and trebly due to it's placement so close to the bridge but that I can work with it using the blend knob. I also find that it has the noisiest pickup hum if the power is even remotely dirty. But, if the power is clean it's an absolute joy to both play and hear.
The 4001 is "typical" playing and sounding like most post-'73 4001 basses except that it was made before Ric stepped up to the beefier neck in the early '80s and, as such I think is easier to play than those from the '80s. I changed to neck pickup to the toaster-style because I found it gave me a better sound with more options. It has been the bass with which I do the majority of recording since it sounds so good. It has the pickup hum if the power is dirty but not as bad as the 4005.
The 4002 is heavier than the other two but is more visually stunning because of the birdseye maple. The neck is very comfortatble and feels almost the same as my 4001 so it is very familiar. The range of sounds that I can get out of the pickups is amazing but I haven't had a chance to play it with the band yet, mainly due to the fact that a couple of strings were buzzing when I got it and the neck needed a slight adjustment. I'll have it back by the end of this week from being set up and will have played it with the band by mid-next week so I'll have a much better perspective on it's sounds then.
I almost afraid to tell my wife but the Ric bass collection isn't finsihed yet... Although it won't happen in the near future (since I've still got to pay off the 4002) I'm still looking for a 4001 V63 and '68 or earlier 4001. How many's enough? Just one more...