Opinions about razor cuts / Thinning thick hair

The style I've being trying to attain is basically my current hair length and straightened. The thing is, is that when these people straighten their hair it looks very straight and defined.

 

Mine generally looks poofy takes a lot of volume and not so straight. Don't get me wrong, I like volume actually, but when its amorphous volume and doesn't give that straight look, it just sucks.

 

I started getting my hair razored to help thin it out and make it easier to manage. I've had it razored by the same hairdresser I think 3 times. The cuts have all turned out differently, the first helped significantly but my hair was still very thick, the second a couple months later was nearly perfect. The third time she totally went overboard and it looked like crap, really short layers and so much razoring. But I've noticed with all of them after a couple washes or so my hair generally gets poofy again and it sucks. Like with the last cut my hair was at first very flat after the cut, then if I straighten my hair a month or so later it gets pretty poofy. I do use product when I straighten and deep conditioners.

 

 

So I was wondering what people thought about razor cuts. What is the best way to thin out super thick hair that is difficult to manage? Do razor cuts cause a lot of split ends?

 

I notice razor cuts expose a lot of ends because the razor cuts hair at different lengths, and I notice that once the ends start splitting and I try to straighten my hair my hair will look rather ROUGH because my hairs end at so many different lengths and my hair will look not so straight and not so nice. I like the choppy effect of razor cuts cutting the overall length but is there any other alternative to thinning out my hair? Perhaps razored at the very ends only and thinned elsewhere by thinning shears?

 

Thanks