Heavier weight + fewer reps + compound exercises are great for building strength. However, I can't say it will help with weight loss...in fact it may even lead to weight gain (including fat, not just lean mass). You need to eat more to have the strength to get through the workout and progress to heavier weights each week. Aside from the fact that working out also makes you hungrier.

If the primary concern is weight loss and the secondary concern is strength, I suggest sticking to the elliptical and maybe spinning classes (spinning is great for weight loss) and complement that with Pilates which will strengthen your core and improve flexibility.

People often mention HIIT but I have never tried it so I cannot comment. It may be worth looking into.