I have used both to print cards from RR. Lightroom does a great job with the actual printing -- you just need to carefully set up your template and make sure you understand which way is up when you print
I have separate templates for horizontal and vertical cards, too.
For me the major issue with Lightroom is that I can't figure out how to print text on the back of the card (of course it's the same side as the image, but it's the back once folded.) I want a title and caption, but AFAIK Lightroom won't do that in exactly the spot I want. I'd love to be wrong about this.
In Photoshop, I create a document for each size and orientation of card, put guidelines in all the useful places, and save it out as a TIFF file. Then I open, say, the 5x7-horizontal document, insert the photo, add some text to the "back," and print it. Then I do a Save As for that specific card so I can print more copies later. I get more control this way, but it's not quite as seamless as using the LR print panel.