Preco

I just purchased a Cannondale Synapse 105 (compact double) Sunday. My 1st bike had a (triple), the drive train seemed to be allot quieter in less I was crossed chained. On new bike when I am in small ring front large cog in back seems to be noisier not much but more.
Bottom line is there more noise on compact double than the triple.
It looks to me that the chain angles are steeper. Also I was told there were just as many usable gears on the double as on the triple. It doesn't seem like it.

stapfam

On the gearing--The lowest on a triple will be 30/27ish and on a compact it will be 34/27ish. So gearing on the double is higher but this will only affect you if you have severe hills in your area.

On chain noise---If you cross chain by using the big ring on the front and big on the rear you will get noise---Or small/small will cause the same. But if you are getting chain noise without cross chaining then the noise you hear is probably from the front derailleur not being aligned properly and rubbing on the chain. Simple adjustment to make by the shop so should not be a problem.

I have triple and compact double on various bikes and I prefer the compact unless I need lower gears. The range of gears is not a problem but does take a bit of adjustment. Main one being that when you change from the big ring to the small on the front- there is a gap of about 4 gears to get the same gearing. You soon get into the habit of simultaneously changing up 3 or 4 gears on the back when you drop from the big to the small ring on the front---Or vice-versa.