Not entirely true, theres always gonna be mild diff in flow, when you change the IC .. but overall the air moves at whatever rate of flow the unit has(size of tubes and core) The upgraded tmics will have great flow.. but, not always awesome cooling, The reason why the top mount is a tough sell, is you can't ever change out units, and it soaks up heat like a mofo at stop lights etc... Maybe in Canada it won't matter as much, but in ca where it gets super hot, top mount units just boil over the moment you stop driving. And for the current price of the CX kit, it's fairly cheap.
With the cx kit, you can install it, see if you like it, then add a garret or other brand of IC core to the piping kit.. It's all relative to your needs, finances and mods.. So, it may not be perfect for you, but worth a look.