1. you will not be annoyed/contacted in any way (according to my experiences) during your stay except during the presentation.
2. the presentation is 'fairly' hard-sell - but do not under any circumstances buy (see point 3)
3. if you ARE interested, get as much information as you want from the salesperson and then go to
www.tugbbs.com to get all the info you'll ever need about timeshares and Marriott - with the most important point being buying 'second-hand' is at about a 90% discount so don't even consider buying while you are there.
4. If you go into malaga I'd highly recommend 'la skina' restaurant - Michelin star but not too pricey, and I was very imprrssed with the fresh and creative cooking we experienced there.
(btw, took this offer twice, purchased the second time, found out about
www.tugbbs.com after we had purchased, and now regret not the purchase, but the fact that we purchased from marriott directly at such an inflated price - so comments above are to be regarded as "do what I say, not what i did"

)
best of luck whatever you decide and feel free to ask more questions here or via pm.
(I have no association whatsoever with la skina restaurant, TUGBBS or Marriott.)