Diminished tubes are the way to go....
But benefits to standard tube rafts:
1. For paddle rafting a 12-14 foot raft, guiding from the stern is a little more comfortable, you maybe sit a few inches higher, and us older guides are just used to these dimensions. However if you are paddle guiding a 15, 16, or 20 foot bus with massive tubes 22" or wider, with8 to 12 customers, the diminished tubes are much better to keep your paddle in the water.
2. Stand tubes are easier to control surfing in holes...and less scary.
3. If it is cold, the standard tubes block a little more spray from waves and big hits. Keeping front passengers a little happier.
4. Standard tube rafts don't get so deep entering big holes/hits, so you may punch through the big stuff a little better.