I've been using Aperture as my primary Digital Asset Manager for many years now, but I've recently started to branch out into using Capture One Pro for a lot of my RAW image conversions. Aperture's strengths are in areas like deep asset management/metadata, overall depth of adjustments, and the way its various GUI's are easily pulled up and sent away with the press of one button. Where I find Aperture to be lacking is in a couple of "finishing" steps, like output sharpening and exporting multiple sizes/resolutions simultaneously. This just happens to be some of the big strengths of Capture One. Here's how I've reconfigured my entire library to easily take advantage of using two different RAW convertors.
My work computer is a Mac Pro, connected to a RAID 5 SAN, with a 4 drive RAID 0 internally set up for maximum speed. All my different bits of work reside on the internal RAID 0, which is regularly backed up to the RAID 5 SAN. Originally, when I was just using Aperture for my DAM (digital asset management) I was importing all my photos as managed files, meaning that Aperture created one large library that contained everything, my RAW photos, JPEG previews, metadata, adjustments etc... This is a great no-hassle way of doing things, and is how I operated for years. The problem with starting to use Capture One is that I wanted to be able to share all my original RAW files with both applications. This is where using Referenced Images comes into play.
Referenced Images refers to (no pun intended) setting up your own system of DAM and telling your software to 'refer' to those files instead of importing them directly. Things can get a little tricky, and due diligence is required to make sure nothing gets out of place or not backed up properly, but for what I'm trying to achieve, it's the only way to be.
As you can see, this is a birds-eye view of my folder setup for all my photography. The most important thing is my RAW Archive. In here, I've arranged all my RAW photos by either project or year. Every client gets their own folder under "Client', and all my general shooting gets placed by year, month, and day. From this RAW archive, I can point both Aperture and Capture One to refer to the same photographs, therefore the only thing inside the Aperture folder is my Aperture library holding all the adjustments, previews and metadata. Inside the Capture One folder is my C1 libraries with all the adjustments I make living inside those C1 libraries.
Once I finish editing all my choice photographs, whether that be through Aperture or Capture One, I export the finished products to the Output folder, with sub-folders for large format printing, web uploading, etc...
This is a pretty involved workflow, but once it's put in place, I find that the benefits are easy to reap, and it is a very solid system of managing all my photographic assets. Nerdy, I know, but a lot of photographers who don't have a system in place have trouble finding things and it becomes very easy to lose stuff amidst the thousands of photographs we might take in a year, or sometimes even in a month.