I finally changed my original DC spindle for the Dewalt 611 I bought over a year ago, and apart from having to run a file through one of the eccentric nut holes on the spindle mount and turning up the z voltage pot a little it worked right first time. The Inventables sticker thing on the front of the mount looked like it was crafted with two blunt rocks, and fell off before I even got it mounted, but only a cosmetic concern.
I was happy to find that I could buy m5 lock nuts here, so I also did the swap the bolts around and use a nut mod for the Z eccentric nuts, using my specially imported Blue Loctite. I just used ordinary bolts, as I can’t buy button head screws here, and although they don’t look so sexy they turned out much easier to tighten up and adjust.
During my second test run, after upping the voltage, I clicked Use Last Home Position, but I guess I had moved the carriage manually or something, and the machine plunged straight down to about 12mm, and plowed through the test board without missing a beat. I think the 1.6 mm depth of cut for mdf is a little conservative.
I’m hoping to be able to afford the one piece x axis soon and then will retighten my belts and calibrate the voltage and steps properly, but even as is I am getting around 99% accuracy.
I’m also reading the posts about dust collectors, as the Dewalt blows mdf dust all over the dining room, and I think my previous system (manually waving the vacuum cleaner over the job) is no longer satisfactory.
As several people told me before, the mini spindle vs. the Dewalt is really chalk and cheese.
When I made the change my first thought was “I have made a sawdust machine!”
If you didn’t hae dust collection before you will need it now 
Also the power of the Dewalt will let you cut at speed that require the gantry upgrade. There is a no drill trick someone came up with using washers and long blots threaded in the gap between the gantry rails that may help in the mean time.
I recommend ordering a 1/8" collet instead of using an adaptor. The one I used had terrible runnout.
Final look into ordering some spare brushes now, so you will have them on hand when they need changing. 
Make sure you set the angle of the dewalt to your frame.
There are many explanations on the forums here.
Search for out of tram and calibration of the hardware.