Wow Howard, you sure know how to get a conversation going. =)
Being a developer myself, I know there are both sides of the coin here. Paige brings up some very valid points. Initial "default" configuration should be very painless and (IMO) should be doable without documentation. Customizability should be the hard part that requires doc reading, possibly research, etc.
I disagree that a user who cannot mess with INI files blindfolded should not be allowed to use anything other than mame32. I suspect (hope?) this is an exaggeration. The really good software out there, speaking of software in general, doesn't make you do all sorts of mindless things the computer should be able to automate for you. Yes, there are always exceptions, but that line is pretty fuzzy and (again, IMO) changeable from developer to developer. FE's are far from perfect, and thus we see all sorts of variations and derivatives out there.
From the dev's standpoint I can understand a lot as well. This is a labor of love, and once it's "good enough" for them (sometimes much more functionality than the dev would use!) they consider it complete. This again varies from dev to dev, but it's only worth a certain amount of time to dedicate to this stuff. If I may use minwah as an example (apologies in advance)... There was some discussion about exiting windows with the power button not working because of how MAMEWAH was coded. A solution was found (and even an example of code was given), but it's not high enough on minwah's priority list to get in there anytime soon. Some people would say this is bad, others could care less. It's certainly a loss for the potential MAMEWAH users out there who would care, but is that enough people for this to merit the time and attention? Only minwah can decide. If he gets enough pressure I'm sure this will get fixed sooner. Anyhow, I'm getting offtopic. (Again, sorry minwah.

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For me, my MAME cab is a hobby. I am using an older version of mamewah simply because I don't want to take hours to re-setup everything. I want it to work. It's not perfect, and not what I'd call optimal, but it gets the job done with a minimum of effort. I have a saved backup of the current "working" setup so that if anything goes wrong I trash the current incarnation and go to the backup. I've experienced a lot of these "learning curve" pains and I'm not sure all of them should be there. Paige, I share your pain. =)
As an aside, is there a technical reason for not being able to check the version of MAME a FE is running? There are possible problems with mame derivatives here, but I'd expect that ot be the exception rather than the rule. Couldn't you "automagically" set this in most cases? And default to the new XML way if it's undeterminable? This seems like fairly trivial coding.
All that said, I want to thank the FE developers out there for making this stuff available to us! It's a ton of work to do, and it -IS- appreciated. Thanks for your efforts.