Always quick to blame the software, never the hardware... sometimes you may have the most up to date hardware, but if you got the wrong parts joined together, expect issues, and one of the main culprits is either the wrong or bad RAM or an under powered PSU, and I do not mean the Wattage, I mean the AMPerage, something inexperienced builders always go amiss...
But yeah, come on in defense of both applications I must say, since they fly into the thousands of lines and I mean tens of thousands... some issues are going to get through or have some guy say 'We can fix this if enough people complain about it post launch' etc...
But so far I cannot recall many crashes with FPSC, then again I have not made anything huge with it
But yeah... we must always take everything into account...
Personally I am not a fan of UDK, and definitely not a fan of Unity... I may experiment with UDK at some point, but that may be a year or two from now. [Or Six months given my past advances in development]
Anyway I shall finish rambling now >.<