I have both Mona 2 and Elise 2. Mona 2 is great, but Elise 2 is even better. They're both fabulous and I don't think you could really go wrong with either. Elise is stronger and has 2 motors, whereas Mona only has one. But Elise is bigger and might be a little large for some people.
I felt like I was still able to get nice G-spot stimulation from Elise, even though it's not as curved as Mona. If I could only have one I would choose Elise, and that's the one I would recommend if you're fine with the size.