Since upgrading to Yosemite Photoshop's editing boxes are slow to react when keying in scaling percentages and changing text point size/leading. Any suggestions would be really appreciated!
Which version of Photoshop are you using? Have you tried changing the font and clearing up the Font cache?
Refer Troubleshoot fonts issues in Adobe Photoshop CC, 2015, 2014, CS6, CS5
Hope that helps.
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