Midland AVP-H4 vs AVP-H3

Which of the two headsets, the Midland AVP-H4 or the AVP-H3 would be the better choice. I will be using the headsets for staff members running a convention. They will be wearing the headsets for about 15 per day. Since the cost is the same, I think comfort and performance would be the deciding issues. Has anyone used either or both of these?

I have actually used both, and I prefer the H3. I think it is more comfortable and easier to use.