So, I went ahead and made the change last night, and my earnings have increased quite a bit! I'm also testing on a few other sites as well to see if I can experience the same increase.
I guess the reason I never made the switch to both text/image ads was for the fact that I didn't think there would be many good image ads for this one particular site. Apparently I was wrong. I plan to keep an eye on this over the next few days to see just how much it does increase my daily income overall.
Google claims that most people see an average increase of 4402% in eCPM earnings when going this route - yes, over 4,000 percent! So, if it continues to remain steady, this site could earn almost double. No arguments there
If any of you haven't yet, give the text/image ad mix a shot. You may be surprised at the result.