I am facing currently the same problem.
When you want to start your macros within TC, or in other words , creating a .dll, there is no chance using VB6 with TC19-64. VB6 need the reference to Imsigx19.dll (which is a 64-bit .dll in TC19-64 bit). That is not possible.
>>So just how hard is it to port a VBA macro to VB6? Is there a tutorial somewhere? <<
to create an .exe is very easy. copy the code, reference in VB6 - thats it.
to create the .dll is more complicate.
>>I'm surprised it runs slower, I always imagined an EXE or DLL would be far quicker.<<
I compare the speed with the vba-ide within TC, which was cancelled in TC12.
the .exe run much slower then vba macro within TC.
the .dll is almost the same speed.
I decide to stay longer with TC18. But in the long run I need a solution for 64-bit. I installed VS-2010 express , with is free. But non of the samples provided from IMSIdesign (in the SDK folder) work with TC19-64 bit.
I asked IMSI for support http://forums.turbocad.com/index.php/topic,8840.0.html
>> Would I only want the 64-bit version if I wanted to throw a lot of RAM at it?<<
sure 64-bit. To use more RAM is the reason for 64-bit.