The biggest reason I'm looking at MPPT controllers is because I only have a limited space for panels, so I have to make use of every single watt.
If I were using a Harbor Freight special (three 15 watt panels + a low end CC) to keep a vehicle's chassis battery topped off, PWM is fine. However, where square footage is a very precious commodity, paying the extra for MPPT may be the only way to go for getting the most energy from a panel set.
On one hand, I am interested in experimenting with some of the Chinese MPPT controllers. The reason is that for solid state items, China is pretty good at. Their own populace is trying to move to solar from coal, so solar CCs are improving just for that reason.
Of course, there is the fact that a CC is a long-term investment, but sometimes it can't hurt to experiment.
