I've used AutoPIPE for about 6 years and Caesar for about 3 years. Currently using Caesar. Every time I use it, it strikes me how aged its user interface is. It seems to have been designed in early 80's for a DOS system, and never really thoroughly updated to a current computing environment.
AutoPIPE is fluid. You don't have to SLOWLY jump from window to window to see movement, to edit model, to see stresses etc. The computing engine is order of magnitude faster. You make changes, you recalculate in 3 seconds, and you almost instantly see the changes in the stresses, forces and movements. No searching through spreadsheets necessary. You select a point and you have ALL the information necessary right away. And if you have a data spreadsheet open, then it goes to that point right away as well (imagine that!). I think the quickness and simplicity of making changes makes you try many different possible design changes, makes you see their effects easier, and hence, makes you a better stress engineer in the long run.
Speaking of making changes in the model, as you might guess, it is MUCH easier. You don't have to worry about going through a spreadsheet trying to figure out the locations and magnitude of changes. You graphically select and stretch, pull, mirror, copy and paste, etc. Each operation takes seconds instead of minutes. Although I noticed recently Caesar is trying to copy that functionality (graphical stretching/moving), but it is still very cumbersome.
And node numbers? who cares? You don't have to worry about those almost at all in AutoPIPE. And why would you? Why would you be limited by something that should be handled by the software internally? I thought computers were suppose to make our lives easier.
As Tye mentioned, the report output is handled differently. Once you're used to Caesar I suppose, you might find AutoPIPE lacking. However I don't think he is aware of all the output options, including very selective result filtering of AutoPIPE. I find the reports more than satisfactory. Also the way you view your results is more through the graphical representation of stresses and strains of the model. I find that much more intuitive, quicker and more useful than searching through tables of numbers. The graphical representation in Caesar is fairly atrocious. While in Autopipe you can get both visual representation of stresses, strains and exact numbers of any point you wish, in the same window, instantly. MUCH more user friendly.
I haven't done underground in Caesar, but I've done it in Autopipe. It's fine, providing you have the soil properties. Either way it's very much a guessing game because of the ever changing soil properties.
In conclusion, I view Caesar II as having one of the worst and least user friendly user interfaces of any program I've ever used. It is a necessary evil in the career that I've chosen, because of its popularity (it started earlier I believe, and has had very good marketing, while AutoPIPE's advertisement and promotion has been sorely lacking). Hopefully it's something that's changing. Last job (5 to 10 stress engineers) I helped to move over from Caesar to AutoPIPE.
Once you're fluent in AutoPIPE, it is an order of magnitude faster and easier to use. I would suggest you try it and stick with it for a while. Try using the keyboard shortcuts for building and editing models. And of course it would be nice if there was someone on site who could show you the basics in a day or two. Yes of course AutoPIPE is not perfect and has its quirks. But mostly they are easy to handle and nothing major. Caesar's whole user interface on the other hand seems to be one big quirk.
Hopefully I didn't ruffle too many feathers. Of course this is only my opinion, and I realize there are die-hard Caesar fans out there.
Cheers!