Carlson OEM

It's hard to judge without knowing your CAD background. My suggestion would be to install a demo of OEM and see if you can function in the constraints.

I started with AutoCAD LT and Carlson Survey 2000. Then moved to LDT and then Civil 3D and now for my own business am back with Carlson Survey OEM.

Are there some things I miss? Of course, but they are not worth the expense to me. I am actually struggling to remember vanilla AutoCAD commands that I used to use.
If anything we had Terry Dotson's Toolpac, and I miss some of his shortcut LISP commands.

Keep in mind that OEM (and LT) is a closed solution, meaning you cannot add anything onto it. The biggest thing is what you're used to. If you are used to having a full CAD engine and customizing it, you might find OEM frustrating. If you've only used a handful of Carlson supplied tools all your career, OEM would be fine.

My experience is that the answer to your question is a big, fat, NO!!
I lost NOTHING. I gained MUCH!! First thing people will tell you is that you lose your Quick Keys. Wrong Answer. There is a fix that is listed on the Carlson website in the Discussion Groups.
You cannot use LISP routines in the OEM version. Most of the lisp stuff I had was already in the Carlson package OR they had a better way to do it built into the software. I just had to find it and learn to use that tool.
If you liked LDD, you'll LOVE Carlson Survey OEM. AND the Carlson kernal is NOT really AutoCad LT. It is MUCH stronger than that.
Bottom line: look at the cost of the package. Save time, money and frustration and go with the OEM version. Get the third party books from Jennifer DiBona or the book by Rick Ellis from cadapult.com and learn how to use the stuff. Better yet, go to one of the Carlson College training sessions and really learn the software. Either way will be the best money you ever spent and that training will pay for itself in no time at all.

What's OEM? Is it different than Embedded ACAD? Do they still offer the ICAD version, that can also be installed on C3D?

I could be wrong, but I believe that the OEM version is the version with embedded AutoCAD. I use Carlson Survey 2008 with embedded AutoCAD. At first I missed the lisp routines that I had been using in AutoCAD R14 with Eagle Point, but soon learned that most, if not all, of the things I was using lisp routines for was included in the Carlson software.

I have found that a few things mentioned here on the forum are not included in the "embedded/OEM" version, but I have always been able to get the job done with out any noticeable sacrifices.

I like it, and will be upgrading soon (hopefully).

Thanks all. I do use some LISP routines, but probably nothing I can't live without. I'll get a trial version and give it a whirl.

Thanks. I've been using the embedded ACAD version since 2004. I haven't found anything missing that I need.