We have glass over the middle part on our sumpless 120g. The back and front is covered in eggcrate. I can't count the number of times we've looked at the glass covered and wondered why it was all splashed up. Then I remembered the reason we covered it completely was to prevent our fairy wrasse from jumping out. He's been with us for almost two years now
Also, we clean the glass during weekly maintenance so it doesn't get dirty.