When u accelerate, it will increase the RPMs to highest possible. When u cruise, it will take it down to lowest possible. It is a continuously variable transmission, which varies continuously as per your driving. It is usually used in econoboxes, not for racing etc. It is designed to get better fuel economy.
As for ur comparison with Move and N-one, those are 660cc Kei cars. That is a different category altogether. I don't think a comparison is valid. If anything, you can compare it with 1.6 CVT Corolla that is offered abroad, or the 1.8 that we have here. I don't believe it is going to be sluggish, or a fuel guzzler. I have even got upto 19 km/l in my 1.8 CVT Altis on long routes, and around 13-14 easily in city driving. That is a 138 hp engine on a heavier body. I think the Yaris is going to be alright, and give similar economy and performance here.