It's not as if this subject needs another post, but from someone who has no agenda (and no HD wrenching experience until my *&%@$# bike comes in), I think the gear/chain argument has a lot of passionate, but not necessarily scientific posts.
It looks to me as if your choice of gears or chains SHOULD hinge on some objective you are trying to achieve. For instance, if you want the peace of mind that never having to check tensioners gives you, gears are a really good choice. If you're running a competition bike, whose performance may be measured in tiny fractions of a second, gears may be really necessary. If you are running a viciously brutal cam, gears may be your best bet for longevity. If you simply like the experience of trying new "hip" things, gears will satisfy your need. And gears will definitely let you showboat in front of all your friends who don't have them.
On the other hand, if you are doing a mild build, if you have a budget for your project that forces you to get the most "bang for your buck", or if you don't like the idea of tearing your bike down to install gears that might not fit or work properly without "fussing with it", gears are likely an overkill. Lots of high performance engines use camshaft drives that are not gears. Instead, they use belts or chains. Not to mention that NO ONE has ever published scientifcially credible results to prove gear drives yield greater power.
In my case, I am doing a mild "Hippo" build, and as an engineer and a mechanic since childhood, I see no compelling reason to switch to gear drives. My choice might change if I was doing something more radical to my TC 88 engine, but my mild build is easily handled by chains with little or no worry about
It simply seems that gear-drive cams are very well suited to some people/objectives, but are not the Holy Grail for every situation.
I suspect this will draw passionate responses from both camps, but I really have no quarrel with either position. Just don't tell me my build is doomed if I don't switch to gear drive. Chains are an intelligent choice in some applications. Gears are an intelligent choice in some applications. Just remember to make your choice on rational grounds, not "keeping up with the Jones's."
My upcoming build, for which I have almost completed ordering parts, will be chain drive because:
1) it requires less experience and expertise than gears,
2) it is cheaper
3) it is not plagued with noise problems
4) I'm only willing to pay for modifications that the "butt dyno" can feel
5) were it not for unpredictable tensioner wear, gear drives might not even exist
6) tensioner wear can be significantly reduced by chain polishing.
7) years of experience (non H-D) have taught me that it's easier and certainly more satisfying to upgrade in steps. Downgrading after-the-fact because your initial choice of components was not outstanding, is NOT a pleasant experience.
Cams or chains? There is no universal answer, so be sure you know what you are shooting for before you start.