Hi SC,
I agree with you about the differences between the n6.1 and the HTour. I've never played the HTour, but I can tell you the nCode nTour version definitely absorbs more shock, although probably not as much as the n6.1 (there's no replacement for sheer mass). There's no question the n6.1 because of its heavier static weight definitely gobbles up a lot of impact. I would say if you are really playing long ground stroke games with powerful hitters, the n6.1 might be the racket. My only problem in that scenario has been getting the n6.1 around fast enough. I have quick reflexes and thus like the racket to respond as quickly as I do. In that department the nCode 6.1 just doesn't cut it. And FWIW, it's not the static weight that is slowing me down, it's the balance. I switched to the POG which is 12.4 (.2 oz. heavier) and had no problem. Same goes for the PS 85 at 12.4, comes around very quickly, just small sweetspot. Both of those rackets also absorbed a lot of impact so were very easy on the arm in heavy hitting.
"Anyway, I've talked about my experience with the n61 and Htour mainly to lead into this question. Do you think the the 03 Tour plays like a combo of the two?"
To be honest, there's not much comparison between the n61 and the O3 Tour. As you've said, the n61 is very solid, very stable, absorbs tons of shock and is very precise (again because of its weight). It handles beautifully at the net and delivers heavy serves. It's a great racket!! I'm just watching Gaudio use it at Hamburg. The O3 will feel much more like the nTour. It has a much lighter feel, very quick coming around. It is very solid feeling and absorbs a lot of shock, I'd say almost as much as the n61, but because it is a lighter racket, it will never absorb as much without some extra weight. The O3 with its 100 sq.in. head gives more options serving, wonderful slice and topspin and moves through the air very easily yet with more control than the nTour. The n61 gives more weight and slightly better control and placement, but feels heavier in the air. With the n61 you have to set up the swing properly and then let the racket go where it wants to go, it's not a racket you push around! (Same was true of the Tour 90 and the n6.1 Tour 90 - wonderful rackets, but rather unmaneuverable. Federer's "n6.1 Tour 90" is completely different from the production one.)
"Related to that question is how does the 03 Tour hold up in long groundstroke rallies?"
I've only played one match with the O3 Tour, but found it very comfortable on the arm and only felt very slight vibrations when mishitting heavy ground strokes. Anytime I was hitting in the sweetspot, the frame was solid as a rock although necessarily not has deadened as with the n61.
"Finally, can you comment on serving with the 03 Tour and also how it volleys ?"
I got generally more serves in, was knocking the racket out of my opponents hand and also had plenty of spin and placement on second serves - I love the way this racket serves. However, it does not serve as heavy a ball as the n61. I plan to add about 3 grams of weight to the O3 to add that extra weight to the ball. Volleys are amazing because of the light weight of the racket and the phenomenal quickness. The O3 is more a players racket though, i.e., lower power than the tweener rackets, so you do have to put some power into volleys or they won't make it over the net on their own. Certainly the n61 is the same volleying but more so, you don't give the racket some pep at the net and the ball won't go over.
To me the O3 Tour has a "unique" quality which I think will make it a real keeper. The racket has a very silky, smooth, solid feel which inspires a lot of confidence taking balls out of the air, doing overheads and chancy returns of serve. I'm sure it can be used to crush the ball hitting as hard as possible, but I found that a more fluid, relaxed approach and using a more biomechanical body motion created a flow between the arm and racket which created plenty of power with lots of variety. Little woo-woo there maybe, but that's the difference I've noticed going from the "heavier" player's rackets to the lighter one's like the O3 and nTour; the ligher ones seem to play better as part of the whole motion rather than pushing a "log" around on the heavier rackets. FWIW.
Anyhow, lengthy reply, but I hope helpful. I've played on most of the Wilson "player's" rackets and love them. I picked the O3 Tour because it combined solidity with quickness and is a very forgiving racket. For me, the O3 (and the nTour) are as close as I've been able to find to the feel and quickness of my PS 85 which is still my favorite racket, but a rather unforgiving little son-of-gun!
Good luck!