One thing that is very amusing between us all "experts" is that a lot of knowledge comes from past experiences and "how we feel." I can tell you that when you start dealing with multiple languages, each one changes your perception, and whilst you move from one to another, this begins to make things more fuzzy.
The CSTR function is a derivative from the old BASIC days, back in the 1980s. BASIC stands for:
Now, the CSTR function came about because in those days, each instruction was compiled and held in its interpreted form in a minimal amount of memory. The fewer letters you used for a function, the less memory it consumed and the larger you applications could be. Nowadays, with a couple of gigabytes of memory and 40 GB of HD space, this has become less of an issue.
The .NET Framework attempts to standardize the way in which functions work. And to be honest, whilst you use CSTR in VB.NET, if you decide to make the move to C#, you'll find that a lot of blankets used to pad people in the VB world, have suddenly been removed.
You might even notice that with each object there is usually a sub property 'ToString' -- this is exactly the same.
So the quick answer, is no -- it makes no difference; it's all personal choice.
This was first published in March 2003