Kate,
I've been using Aperture since its first release, so it's the key element in my workflow, supplemented by Photoshop when needed.
I do 99% of my printing via Aperture, and have done extensive testing of printing the same file/image by Aperture and Photoshop. I'm still satisfied by the prints via Aperture, am using it to prepare prints for a solo exhibition coming up next year...
The key to getting good prints via Aperture - assuming you have a carefully exposed and carefully processed image to print - involves taking care to study the Print screen, and making sure that you (a) select the correct profile in the ColorSync Profile drop-down list; (b) chose the correct paper setting in the Paper Size drop-down list; THEN (c) click on Printer Settings... then on the Layout drop-down list to choose Printer Settings for the paper and print resolution, next choose Color Management and select "No Color Management," then "OK." (You MUST choose your paper size BEFORE going to Printer Settings since the settings available will be determined by size settings (sheet fed, roll, manual - i.e., rear paper feed). When back at the Print screen, set your Orientation, and make sure the "Scale To" settings are set to the size you wish for your image. (Tip: crop your image to the size you want before sending it to print rather than letting Aperture attempt to adjust your image to the setting in "Scale To." Otherwise, you'll likely get a printed image size that measures differently from what you want and the image won't fit a pre-cut mat opening.) When done with your settings, you can save them using the buttons at the left, bottom of the Print Screen, giving the settings a name such as "12x18 on 13x19 Landscape" (depending on your settings, of course). Next time you wish to print using those settings, just click on the name and ALL of the settings will be invoked.
Invest the time in learning how to set your settings and Aperture will serve you quite well. And since I routinely print on 13x19 inch papers, I've found that the quality is consistently very, very satisfactory, and I use a number of really fine (and expensive!!) papers. Again, I'll be exhibiting prints produced via Aperture.
Hope this bit of info helps. Good luck...
Lou Outlaw