Thank you for your post.
I agree with your assessment and understand the sentiment of your doctor that your medication regimen appears to be otherwise working. Any switch from a stable, successful treatment regimen should be done with a thoughtful consideration of the potential risks and potential benefits.
That said, there is ample evidence that stable switches from stavudine (d4T, part of Triomune) to tenofovir (Viread) are entirely safe in persons on first-line treatment, provided that you do not have any active kidney disease.
It is clear that d4T contributes to peripheral neuropathy and elevations in lipids. The association between the drug and fat accumulation is a little less clear, though there is compelling evidence that d4T use is associated with fat loss (lipoatrophy).
For all of these reasons, d4T is no longer recommended in US, European and UK treatment guidelines.
Hope this helps. BY