Tell me Giloren,
How come you bought a bike with components that needed new components a year later? Did you buy it used? That would be a good reason. If a shop sold you a new bike that was not dialed in I would ask for a different set up and at a discounted price. It is their job, in my opinion, to dial you in in the first place.
I agree that the longer crank arm (175 in this case) is the way to go for you at your height. I would no way recommend the compact drive for your flat landing riding and in fact if you haven't done so already consider getting a 53/42 set up. (Sorry for the lateness of this response. The last three times I tried to log on to active there was some sort of glich.) Why a 42?
Well, the biggest hill you ride isn't even a hill really. I have not been on that bridge but my guess is that you can get up that hill without going to the easiest gear. So as Colbagger mentioned you want a tight block in the rear (say a 12/23 instead of a 12/25 or 27) so that each shift is smooth and drops right into that sweet spot. I've noticed that when shifting from the big ring (53) to the smaller ring (39) that it usually takes two shifts of the rear deraileur to get to that sweet spot. This happens when shifting up to the big from the small as well. With a 42 only one shift to get dialed in is necessary. (On Brown's site you will notice that, in effect, three teeth on the front chainring equals about 1 tooth in the back.)
Around here in SE Michigan we certainly don't have any mountains but we do have some significant hills. Stronger riders ride up them in their 53 but they approach "crossing over" in the rear and many of them ride a 12/25 in the back to avoid using their front shifter. It appears that stronger riders here who have a 39 don't use it much. I have a 42 and I use it. As it is a closer configuration than a 39 my chances for dropping a chain are less too. I've made the suggestion to several riders who were opting for new chainrings to consider getting a 42 instead and everyone who did so loved it. Only one guy swapped back and that was on the bike he took out and leaves in Arizona for long mountain rides.
When I rode to LA from Marin two years ago I rode my 53/42 and had only a 12/25 cassette for a the climbs in the Big Sur and some switch backs on day three and a long 7 mile climb that seemed to go forever. I admit, on that one long climb if I had one more gear I would have used it but I was fine in the 42/25. I swapped back to the 12/23 (I actually also use an 11/23 most of the time) upon my return and didn't regret having that 42 at all while in the hills around Marin or on the coast ride. (One of my bikes came with an 11/23 and I got used to it. I can ride the 42 down to the 12 without crossing over as it happens. I don't think I'm a sprinter enough to require a 53/11 for sprinting but it works for me.)
Note: Crossing over is when you use your big (hard) gear in the front and your big (easy) gear in the rear or vice versa with small and small. In general this should be avoided. It puts a sideways torque on the chain and is as a result, less efficient and wears (stretches) your chain prematurely.
HEADS UP!
