The one I always get is the 16 oz. which lasts, if I remember correctly, right at a year.   I got my first one at our housewarming party in November and replaced it at Christmas I think.   On other sites (for other fragance brands), I've seen where they say that the 8 oz. ones last 10 weeks but I don't think that's correct.   I have a little tiny one from a fundraiser that's probably less than 8 oz. and have had it for months!    
 
My very favorite Alora fragrance is the one called "Uno".    The Alora site says: 
uno. The sweetest fragrance in our collection, uno is a feminine mix of muguet, sandalwood, musk and lemon. 
I think it smells just like tuberose which I absolutely love.  Maybe it's the sandalwood that makes it smell like tuberose, don't know.  But if you're cautious, I don't think it's "overpoweringly sweet" - besides, sandlewood is not what I'd call "sweet".   Not like some flowery candles that I can't stand....  I'm not much of a sweet fragrance person. 
My other favorite which I have in our bedroom right now is "Tre".  The site says: 
tre. Ideal in the kitchen, tre is a warm fragrance composed of orange, mandarin, vanilla and amber.
Those are the only ones that I've smelled personally so I can't give an opinion on any other fragrance. 
Now that I've read those fragrance descriptions again, I think it's the sandlewood in the Uno and the amber and vanilla in the Tre that draw me to them.    
I can tell you that I get compliments on the fragrances every time someone new comes in my house and even sometimes from the same people.  I used to do the same thing at my best friend's house.   She first had the Uno and I would purposely walk through that room just to smell the diffuser.   Fell in love with it and had to have one (now several) in my new house! 
If you decide to get either of these fragrances and really hate them, we could possibly make a deal for me to take them off of your hands.   I don't need any new ones right this moment but I think if you seal it back up, it would stay good.  Keep that in mind.  
