I don't know of a white paper that addresses the List Report Wizard versus the Summary Tables Task, specifically, but there are a bunch of PROC REPORT versus PROC TABULATE papers from previous user group meetings -- a few folks had an ongoing series about which was better. (If you Google search on the string: Battle Titans Report Tabulate
you should find the papers.)
The List Report Wizard in Enterprise Guide seems like a good "starter" code generator -- since it doesn't surface COMPUTE blocks the wizard is only doing simple summary reports or simple detail reports. The Summary Tables Wizard allows more nesting via drag and drop -- and more customization via the windows.
My personal tendency, for either procedure, is just to use code instead of the Wizards. I tend to prefer PROC REPORT (for the customizing, the COMPUTE block and the CALL DEFINE), but if I have a lot of slicing and dicing and nesting in my cross-tabs, then I prefer TABULATE.
But for the beginner, I think the biggest issue that I've heard about (and it surprised me) was whether they wanted the box area in the upper left hand corner of the table. For some folks, it doesn't matter that the BOX is there -- but I've had some students switch to PROC REPORT just because they didn't like the big empty box -- seriously -- the BOX area was a deal breaker for them -- they wanted the look that they got with PROC REPORT.
The second issue that I've heard about is changing the code -- some people find the PROC REPORT code easier to understand than the TABULATE code -- if and only if they have to change the code. The TABULATE code is more abbreviated and "algebra-like" with all the * and = in the TABLE statement. Even though the REPORT code is more verbose -- the existence of a COLUMN statement makes it clear which variable will come first on the report row, which second, which third, etc, etc. And then the explicit DEFINE statement makes it easy to see what statistic will get used for a numeric variable, the usage for a category variable (ORDER, GROUP or ACROSS).