We have produced good results on our ACE machines. We keep 2 of them constantly busy, one for regular solder and one for pbFree. Customer service has been good as well. Be sure to use the Nitrogen feature, and invest in a N02 generator for your selective solder machine. ACE might be considered a simpler, more entry level machine, but ours are workhorses, and rarely down for more than regular maintenance.
Agee with Hegemon. We also have two machines from ACE. They run most every day, all day. Good machines, great tech support. I would recommend the drop jet option for any no-clean operations as you'll need the extra concentration of flux to make it work.
We have many Pillarhouse Jade Mark II's in our facility. Lately design engineers have taken a liking of huge ground planes in boards. Quite honestly with topside heaters some of these boards were impossible to solder. True you can preheat with the nozzle but that will take time while I can preheat the board while I'm fluxing. What I'm saying is get topside preheat..