I don't normally use Excel but I have it in Office 2008 as well as Office X. I just tested both and had no problem printing in OS 10.6.5 although I can confirm your complaint about the slowness of Excel X. Print Therapy has solved some weird problems for me and it has a seven day free trial.

Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365