I am going to document my photography workflow every once in a while.
1. I use iPhoto as my main photo library and for sharing photos using Flickr\AppleTV, ordering photo books, calendars and so on.
2. I am shooting exclusively in RAW now but I have over 10k photos in JPGs in iPhoto -- neatly cataloged using keywords, folders, albums and smart albums
3. I use Aperture as my 'digital darkroom' and do all processing here (non-destructive and all apart from the RAW editing options)
4. From Aperture perspective -- I have a folder for every month and then a project for every week under it. I roughly take 100+ photos a week. I rate them, stack them and do some processing on the ones I rate 3 or higher. I have smart albums inside each week's project. The smart album lists images with rating of 3 or higher and respects stack groupings. So I usually end up with around 50+ photos in this smart album.
5. I export photo in this smart album to a temp folder in JPEG and then import this folder in iPhoto.
6. I have smart albums in iPhoto already setup that start showing stuff as soon as I import it. The only quirk here is that iPhoto does not bring over rating info from Aperture and I have to re-rate photos in iPhoto. Keywords are of course carried over.
7. About 60% of my photos are of my young one and the family and the rest are random shoots of whatever. I use smart albums in iPhoto based on keywords to sort them and keep them separate.
8. From here I pick my favorite 5-6 photos and create a web-page using iWeb and post it on my website that is shared with friends and family.9. I also upload to flickr once a month mostly as an additional backup.
10. I also have two external hard-disks backing stuff up on alternate days (nights.)
I have been doing this pretty religiously for the last 6 months or so and have sort of gotten used to it. I find the process works for me but is tedious because I have to maintain stuff in two places. Aperture is toooo slow for me and my wife to use as a photo browser. I like its editing capabilities and hence cannot let it go over iPhoto. Moreover, I love the photo book, calendar and other tools in iPhoto. As far as duplication -- I guess it is just another backup so I don't mind it too much.