they all stink ... i had a superduper LPKF95S with all the gizmos ( multipress , plating installation , the whole shebang.. ) NEVER made a working board with it. NEVER !
Machine locks up , machine crashes , software glitches, communication failures , machine runs into its own toolhandler and bends the snot out of it.
Sure it works , if your boards are 2 inch x 2 inch and you only do contour engraving , and you use their material ( with the double peel-off copper ) and you only do engraving with swuare tipped bits.
as soon as you start playing with depth control to get finer lines ( like 6 mil and 4 mil ) all bets are off...
and as or 'rubout ' .... forget that one totally.
As for a multilayer ... you are going to spend 2 days engraving ( provided nothing screws up ) half a day plating and half a day plus a full night in the oven.. by the time you are done 3 full days have passed. i can get 4 layer boards professionally made , around the corner ( there are at least 4 PCB fabs in a 5 mile radius from where i am : APCT , Sierra , Hunter , Gorilla ) in 8 hours .... since these fabs run 24/7 i send of my gerber in the afternoon , go home , have a barbeque , enjoy the pool , watch some tv , sleep , have breakfast and when i walk in around 9aM my boards are waiting for me ... ZERO downtime , zero effort.
PCB engravers are garbage.
If you are after cheap : with all the chinese boardhouses you can get hundreds of projects run over there for the cost of the bare machine alone ...