Well, I went by the Holiday Inn today to ask my question in person... he said the following:

Basically our standard room and superior room are the same. The deluxe room has free internet. And the executive room has a gift basket, better toiletries and a different bed.
All the rooms mentioned are the exact same size (except the "family room").

I mentioned that all reward members get free internet now and he said... "yea, true. So likely best to just book the base room". Too funny. They charge a little bit more for each room class...and yet, unless you get to executive you really get nothing for it. Unbelievable. No wonder the website is vague.

So either book the standard room (cheapest) or executive. Don't bother with superior or deluxe. I booked standard