We have some fantastic family holidays at Madinat Jumeirah via Sirius points. Dubai is so astonishingly expensive at peak times that these make amazing redemptions - you get around 5c per Amex point if you convert to Sirius.

Note that only the $ IDC Amex card still converts to Jumeirah.

The two connecting rooms we had in a Dar Al Masyaf villa in October were selling, between them, for $3,000 per night and we had 9 nights for nothing.