While I agree that VB.NET is a completely new language, the syntax is very similar to VB6. The structuring of the program is different, and there a lot of features such as generics, lambdas, LINQ, and threading, which can be useful, or may not be. You will always be using generics, you may be using lambdas, LINQ is kind of specialized to database work, and threading...well, that's always a question.

Also, VB.NET is free as part of Visual Studio, which includes numerous languages, not all of which you have to get at the same time. The free version of Visual Studio is the Community Edition, which is really just the Professional edition with some cosmetic differences.

Niya also mentioned that VS is slower to start up, which is true. The VB6 IDE starts instantly, whereas VS will take a few seconds. There's a reason for that. The VB6 IDE is archaic, while the VS IDE is...overwrought. With VB6, you can work with one file at a time, everything is expanded at all times, organization is rudimentary, intellisense is rudimentary, and breakpoints can be unreliable. Meanwhile, VS has so many features that you won't use them all, but they all impact the visual performance such that it has the characteristics of a game rather than a program (slow loading, loads of graphics). It would have been nice if they had allowed some of them to be opt in, rather than opt out, but...most of the features you will end up using all the time.

So, it's a trade-off, but as others have said: If you are maintaining VB6 applications, then you need VB6. If you are doing new development, then go with VB.NET.

Also, you can use it on a mac, macmacmac.