This thread would probably be more fitting on the Other Middle East and Africa Frequent Flyer Programs board, and you'll probably get more answers there; hopefully a heads-up moderator can move it there. I've seen both raves and rants about both airlines. Having flown both, I'll say this:

Business Class
Generally speaking (well, always speaking, in my experience) ET business is cheaper, significantly, than KQ business, inter- and intra-Africa, so if your choice is ET biz vs. KQ biz, go with ET based on price. Since you're not flying long-haul, then getting a flat sleeper on KQ is out of the question for the routes you'd be flying. Both airlines have 1980's generation business seats (~40 inches of pitch, 2x2 layout on narrow-body aircraft, minimal-though-adequate recline considering the flight duration, etc.).

Steerage
If your choice is between ET steerage and KQ steerage, it's a tossup, as the service on both is more akin to US carriers, where they do the drink/meal service and then disappear. Food on KQ is more recognizable than ET. It cannot, however, be characterized as "delicious" by any means.

Let us know what you choose and how it went.

Will