I've have Civil 3D for almost 8 years now and in my opinion it is hands down the way to go if your clients are engineers needing base-mapped data and if they are running Civil 3D also or if they need something compatible for Bentley. I started out building grading models many years ago initially and I could not ever get accustomed to Carlson (I admit it was a very old version) but I know most surveyors love it or TBC. I run Trimble equipment for my older S3 robot & an R6-M4 rover but with some of their conversion items that you can download from their website it makes interfacing with C3D pretty easy.
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Typically C3D runs me ~$2400 annually for a single subscription which includes updates to each new C3D release and it can be installed on 2 computers at once (only one computer at a time can use that license however). But this works really well for me between my laptop on the go/field & the home office desktop plus everything I do is for development so many I interact with either use Civil 3D or the older Land Desktop software which was it's predecessor.
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It will take a little time to learn but youtube & the autodesk C3D forum will help you. I also like some of the built in drainage analysis features (I think Carlson has a similar offering here but I've never played with it). If you're surveying for topographic features and decide to go with C3D then I'd strongly recommend setting up a survey database with feature codes for points & linework - it'll save you time processing & base-mapping things in the office