I've been using the dw660 for a while now and I am very happy with it, but I'm not able to run the machine at night due to the very loud noise it generates especially when using .25 inch bits. I am going to switch to a chinese spindle as I've read that they are much more quiet. I wanted to know from your experiences what to expect when running long jobs. Some of the jobs I run take around 3 hours to finish, and sometimes the machine runs for 7 hours a day with short intervals of rest (10 minutes or so).
Would a DC spindle handle those long runs?
When it fails, should I expect to see some fireworks

?
Would you recommend staying away from those types of spindles?
Cheers!