Whilst I realise that there will not be a definitive answer to my question I would appreciate any comments.

I operate a small CNC machine with Mach 3 software which suits my needs. I am a retired engineer and now it's for hobby use so difficult to justify high outlays.

My main 2 needs are :-
1. Profiling. I generate toolpath dxf files in AutoAD LT and then convert these to
    g code with free software. Not ideal.

2. A friend generates stl models using Rhino which I also convert to g code using
    free software.

I have used Lazy CAM but it's limited.
I suspect that I would be better to go down the route of 2 different items of software.

Thanks in advance for any comments.

a retired engineer and now it's for hobby use so difficult to justify high outlays.

Change your thinking my friend ...........anything that makes YOUR retirement move enjoyable is worth it and need not be rationalised to anyone!
That's what you worked for all those years. It's your time, your income, your enjoyment.  

That said,

Free is usualy limited in some way.
MeshCam and Cambam would satisfy your needs and won't break the retirement fund.

Happy retirement,
BTW.....buy a nice set of magnifying glasses....maybe a high intensity light also.

Retired also and loving it,
RICH

I tried lazy cam which does work. However I really like Cambam. I spent a couple years manually writing G code and Since using Cambam I haven't needed to do that. 40 uses before you need to buy, built my whole machine, then purchased it!

Thanks for the comments (RICH & Gary Lucas)
I have been retired for about 10 years and and agree with RICH's sentiments.
I have downloaded the trial versions of MeshCAM and Cambam and will evaluate both against my needs.

I will give you some feedback in a few weeks.