We didn't have a sampling program when I was there (CS/EEE 2000). But I do remember our ECE241 project using FPGAs that I reproduced using a PIC and showed both versions in the lab just to annoy the prof. We didn't use microcontrollers at all.
My point is that the 16F and 18F are completely different architectures. What I'm saying is it's just stupid to have to start over because you're moving to a new architechure. I use the exact same C++ language today on a quad core phenom chip as I used in my 3rd year CS courses in 1997. And it's more-or-less the very same C++ I used to program an Arduino or higher family AVR chip. Why would I want to waste brain cells knowning archaic details of every chip I've used in between? I can still remember int21h from DOS in the 1980's. That's really useful today. The lower level you go, the more detail you need and the shorter the life of the information.
I'm not even going to comment on your VB6 vs VB.NET comparison except to say it makes me feel a little sick to my stomach to hear a Waterloo student talking favourably about MS (and MS flew me to Seattle for their NT Kernel team in 2000).
I can tell you exactly what it was that convinced me to switch to Arduino. I was working on a PIC project for a very long time to flash and LED at a precisely controlled frequency as well as doing other tasks, reading analog inputs and performing 32-bit floating point division on them, driving an LCD, and interfacing serially with a PC. I never did finish my project. I obviously used timer interrupts for the LED, but I tried every trick I could think of to get everything I needed into the available processing power. Westfw here might even remember how much time on PIClist I spent discussing the project, but it must have been at least 50 hours over 6 months. That was also when I moved to the 18F architecture to try and get the extra power I needed, and that move is what killed the PIC for me. Once I had an Arduino, I had that project finished within an hour, including the initial learning curve on Arduino.
For my second project, just think of the difference between using a PIC CCP module in assembly (16F or 18F btw?) vs using Arduino's pulseIn() function. I was finished my project on the Arduino in the time I'd still be looking up special function registers in the PIC datasheet.
My only problem with Arduino so far is everything has been too easy to program to be enough challenge to be really satisfying.