I am a MVCI member and last year went with my future in-laws on one of these presentations, 90 minutes presentation for 4 days in the sun with car hire + BA miles was a no brainer for us....

The 90 minutes does tend to go over if you get actively involved. If you go for it I would suggest booking the presentation as soon as you arrive so that you can get an early morning slot or later afternoon so that you are not waiting around to go for the presentation... In the my in-laws left without buyinh anything.