Earl, Wofly and all -
I guess that with "not causing any problems", Wolfy must be getting zero defect reflow soldering.  Cool !  I want some of that stuff. 
In my experience, there is always something better out there.  The solder paste manufacturers are beating their brains out and their R&D budgets trying to come up with better performing solder pastes.  What seems to be working well, and has been for the last few months, years..(as in Wolfy's case) might very well be - but most likely there is something out there that works better.  Every time I have done a solder paste evaluation with a client, we always come up with something that works better than what they are using currently - and these are blind tests that include the current formulation as well.  Better wetting, less (or no) solder ball generation, better tack time, better tack performance with a high-speed chip shooter, etc.
I urge anyone who has not evaluated solder paste for over a year to do so - especially if you are using a no-clean.

Phil Zarrow

ITM Consulting 
Durham, NH  USA
www.ITM-SMT.com
T: (603) 868-1754
F: (603) 868-3623
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