Ok, it's like this. If you go on an organised trip with Thomson or any of the other big operators you will not see what goes on in the evening in the square of Marrakech.
The operators could take one of two ways to get there. This could be either by way of the mountains at 5 hours each way or via the recently completed motorway at 3 hours each way. You normally set off between 6 and 7 am so check at what times your hotel serves breakfast.
I suspect that the operator will want to depart Marrakech pretty quickly so you may only get a glance of the activities in the square whilst embarking on your return journey back to Agadir.
Thomsons over here will not have a clue what goes on as all is left to the local guides and rep's.
It is a long time since I did an organised trip to Marrakech but I suspect little has changed in content so have a read of this: tripadvisor.co.uk/Travel-g293731-c120434/Aga…
You have an option of an overnight stay which is the only way you will really see what the square has to offer in depth.
Have you considered a diy trip? This is so easy and you have the option of which time you return on a coach and it is much cheaper. Read the article above and give it some thought as it is what I and other recommend travelers to do.
If you are going for more than 7 days then give this some serious thought as Agadir has nothing to offer by way of comparison.
Edited: 9:17 am, March 23, 2013