Eduardo,
I listened to the Khartago and the Stratos at the MAF driving the Loreli's and they sound remarkably similar. The Khartago uses the same (I believe) board as the Stratos with a smaller power supply, heat sinks and chassis.
I thought the Stratos sounded a less strained and had slightly tighter control of the woofers. Keep in mind that Klaus had the system cranked up pretty high, so it's a tribute to the Khartago that it didn't have any trouble driving the speakers to high levels.
Hope this helps,
Mike