It looks like AC is hear to stay - DC technology is out the door. AC ain't new - most AC controllers come out of Europe where they have been well field tested - I call them 10's of thousands of prototypes for the US market.

If ya' ain't got it - you say it is bad & whatcha' got is good.

Here is a classic example of this.

Worked Allis Chalmers(A-C from 1967 to 1981. When the A-C PWM series (their silver bullet for the competition) was first introduced - A-C had 32% market share in class I. Beat the heck out of resistor & carbon pile controllers. Next year the rest of the lift truck folks installed GE 200 series SCR's controls(or something like that - CRS lite is settling in) - they all ganged up on them with tactics such as proprietary parts, GE parts everyone can work on them etc). A-C's market share, in class I went down to less than 10% the next year and to less than 5% (mainly due to reliability issues - competitors said I told you so) the next year.