The VR3

[Chris H]

Jeff is correct. If you have been planning your dives with a specific decompression model, and are comfortable with the results, you would probably appreciate a computer that uses the same algorithm.  I have used Decoplanner for OC and iDeco and now MV Plan for CCR.  OC we used tables exclusively, on CCR I'm using a Shearwater Pursuit monitoring 3 cells.  I'm very pleased with the Shearwater.  My usual dive buddies dive VR products (Sentinel and Ouroboros) and our Deco schedules haven't varied more than a few minutes on average deco dives.  180ft for 30 minutes for example.  I do like diving with a computer, but never had an issue with tables and a Bottom Timer and OC either. 
Talk to your potential instructor and see what they recommend. 

VR Technology is offering a trade in program that allowed you to trade an old computer for a significant discount.