Dual layer disc compatibility

Most of my DVD projects for distibution are just under two hours, therefore, I am knocking on the door of a full disc and as a result have data rates around 4.2-4.5Mbs and use double pass encoding all of the time.

In order to get a higher data rate I could go to dual layer discs but I a worried about compatibility of playback with my customers because:

(1) The increased data rate might cause skipping in some customers players

(2) I have read of compatibility issues with DL layer discs with some players and also the fact that some players may stop or skip at the break point between the two layers. Does anyone have any suggestions or experience with this one?

I'd always like to make a better product but the trade off for more quality vs. a lot of returns may cause more harm than good. Is the higher data rate i.e., 6 mps vs. current 4.2Mbs going to show any noticeable quality increase or only during those scences with motion?

Once in the past(arond 2003) I when I first started producing DVD's I got a whole slew of returns because of skipping and stuttering video and I don't want to relive that again. Or has compatibilty issues of this nature just gone away with newer technology?

Comments from anyone routinely distributing dual layer dscs would be appreciated