Hi,
First of all, the Nitro 4 is a very different kite than the Switchblade, they are not in the same category.
Personally I don't like the Switchblade because I think it's so slow. A lot of people feel the same. But still, a lot of people like the switchblade and buy it. Personally, I would not consider the Switchblade except for size smaller than 7m.
Regarding relaunch, the Switchblade is probably better. But I did not have problems relaunching the Nitro 4, even in light wind. And if the wind is very low, you can reverse launch by pulling both back lines, which I am not sure you can do on the Switchblade.
Regarding being lively and turning speed, the Nitro is way better.
For low end, the Switchblade is better. But low-end on the Nitro 4 is not that bad, it's just a kite that needs to be worked (different design). However the high-end is way better on the Nitro.
Bar pressure is lighter on the Switchblade. Bar pressure is not that light on the Nitro. I would say it's medium+ or medium-heavy. On the Switch web site, they say bar pressure is medium/light, but I disagree, I think it's above medium. That's also what other testers have said in
the review here.