OK... here is My opinion based on 7 years of racing foams and at least 3 years running rubber tires
1) switching to foams will not make a bad driver good and won't make a bad setup suddenly transform but they CAN make a bad setup appear even worse
2) foams on a well setup car WILL be faster on the majority of surfaces
3) from personal experience adjustments like shock angles don't seem to make as much difference to the handling whereas springs can make huge differences and unless you carry around 50 different tension springs it can be a nightmare to get it exactly right. Ride height constantly changes so it has to be continoulsy adjusted as well as camber, droop, cg, roll-center whereas rubber tires don't need to be adjusted anywhere near as often. Also gearing constantly changes as tires wear.
4) A good setup basic setup can allow a reasonable driver to switch between foams and rubber without a huge change in car performance or handling... My TC3 used to be about 3 tenths of a second faster per lap on foams compared to rubber on bitumen... My TA04R is almost the same speed.
5) Pro drivers here in australia will true the daylights out of a foam tire before running it, espically nitro cars. Its not uncommon at title events to see these people true brand new ellgi's etc down to 58 or 59mm... which makes them good for about 2 runs and at $50 australian a set that gets just as scarey as rubber
In My humble opinion, control tires at title and large events, wether they be rubber OR foam, has been the most intelligent thing organisers of rc racing in this world have come up with... I know a lot of people don't like it but maybe those people should look at full sized racing and actually take notice of the difference it makes to the racing, making it closer and more dependant on driver skill and setup.