Okay, you asked for it. Let me get out my red pen...
Just kidding. This would be holy hell to read if I did the whole thing like this. 
One thing I see right away is that the stem really needs a slight bend in order to flow better. The straight stem interrupts whatever flow there is, and causes my eye to halt along the surface as I'm looking at it. More on this later.
The shank/stem transition needs to be more refined. You've got a slight rounding of the shank and that last ring, which creates the perception of a large gap, even if the fit is otherwise flush. Shaping and sanding, all the way through final sanding, is the only foolproof method to get these perfectly flush unless you have laser guided equipment.
Someone else mentioned the thickness of the shank, but I'm not sure I agree. The thickness looks okay, it could be thinner, but I wouldn't sweat that detail too much.
The rings on the stem look good, but they result ins stem that's disproportionately long in comparison to the shank and size of the bowl. Thsi is somewhat subjective, as I know some folks like longer stems. Overall the length of the stem/shank combo is not bad, but to be in balance, you'd want to split the difference a little. In my opinion, the shank should end just about where the rear ring is, the rings start where the vulcanite currently starts, and the cylindrical portion of the vulcanite should be correspondingly shorter. shortening that length of wood ring at the same time would also bring things into balance.
Speaking of rings, try to get the front and rear rings to be the same thickness. Having them different thicknesses confuses the eye.
This may simply be the lighting or photography, but the color of the wood stem ring does not compliment the color of the briar at all. It's darker, with less detail, and surrounding it with lighter rings serves to accent this. Giving the pipe a more walnut (or brown-ish) staining would solve that.
And, I know I'm going to be in the minority saying this, but the shank/stem junction is too precise. I know a lot of pipe makers strive to hit the perfect junction with clean, crisp lines, but to me that sort of construction is an affront to what should be a fluid and organic shape. I would rather see a smoother transition where the shank is blended into the stummel rather than looking like it was jambed in there at high speed. There are exceptions to this where a crisp transition is attractive - one of brad Pohlmann's bulldog/rhodesians comes to mind. This is 100% subjective though, so take that with a grain of salt.
On this particular pipe, the dropped bowl seems out of place. This is accentuated but the flattened bottom that has been angled slightly. In order to achieve a flowing shape with the dropped bowl, I think you would want to re-work the bottom to complement the rest of the shape.
And that leads us to balance and flow. In this pipe there are a lot of different angles and directions, some of which work together, other of which are in complete disharmony. The top of the bowl does not match or compliment the bottom, whcih does not compliment the shank angle. The angles of the front and rear of the bowl are not in harmony with the stem, even though they are in harmony with each other. When looking at the pipe, my eye does not flow along the pipe. Instead, it stumbles, haltingly along the lines, having to adjust direction at each intersection, while unable to anticipate the next curve or turn. The shape is not calming.
This is in contrast to the rhodesian directly below it in the last photo. There is more balance and flow in that shape. It could use it's own improvements, and I can expound if you'd like (best to do that before finsihing
) but overall it's much more pleasing than this one.
And just so you don't think I'm picking on you.
You managed to hit a very good grain orientation on this pipe. The grain follows the lines of the sides of the bowl very well, and the shape seems well suited to showing off a nice flame grain.
I also think you did a nice job of staining this one. The color is very pleasing, and shows a lot of contrast. Very nice.
Overall not bad, and as a technical exercise, you did a great job. Now you just need to develop the aesthetic side of things and get it pulled together as a "package".
Here's just a part of my collection below. Thanks for taking the time to post your views. Tyler, bust out that red marker and start grading. 
Now that I see you posted your phone number, I just might start chewing your ear a bit. ( now now, don't take that literally. :naughty: )
