There are a whole bunch of truths and mistruths that people take from one application and tag it to another application. If I had one fault with the cnczone, that would be it.
Mechanoman did pretty much nail the highpoints. The linistepper is inefficient and because of that requires more power supply than pwm current control methods. That inefficiency also will manifest itself in heat dissipation. One of the reasons you can't have too high of coil voltage to supply ratio is simply the power dissipation of the transistors.
Regarding "sine waves" Sin-Cosine relationship is used in virtually all microstepping stepper drivers regardless of linear or pwm.
The linistepper does work, it's quiet because there is no pwm switching going on. (Although I'm constantly baffled why people worry about stepper squeel because when your machining you can't hear anything over spindles cutting.)
Unipolar motors do have less pull out torque than bipolar. BUT the issue then turns different depending on drive method. I did a video on rapids to illustrate driving a 6 wire motor unipolar, bipolar half coil and bipolar series to illustrate some inexpensive drive performance differences.
http://pminmo.com/which-stepper-motor
Bottom line, choose motors and drivers together considering the mechanics of the machine your going to use them with.