In my limited experience with DVD writers [compared to many others on this forum]. I played with the BTC drive a bit - it seemed to make [again in my limited knowledge of interepretting PI/PO scans] great looking burns.
Its only drawback [but then again my BenQ seems to have the same problem] is writing near the outter edge. If you scan the media up to about 200 or so MB from the end, there are very few errors. And then if you scan that last 200 MB [approximately - this amount varies from media to media] separately there are a considerable amount of errors here. Just to reiterate - this is a problem with both the BenQ AND the BTC. I burned on my BTC with A07R.
From what I've read CMC mag [Teon] will appear to make great burns and great scans on those burns. However, apparently you didn't always get what you are seeing. I can't think of a good example to compare this to, but it sounds like Teon [and most other CMC mag media] are something to steer clear of no matter HOW cheap is. The old "you get what you pay for" applies really well here. hehe!
Earlier this evening I burned a Fuji MiJ [actual MID Taiyo Yuden T02] on my BenQ. It was an awesome burn. I'd recommend this media if you can find it. I haven't tried burning one of these on the BTC however. Best Buy has been having them on sale every other week or so [but make SURE you get the MiJ].
So the short answer to your question... Other than the fact that the BTC can't read the jitter or PO failures [easily detected by trying to copy the info back to your HD from the burned disc - if it won't copy back - you probably have PO failures], I think the BTC [again with A70R in my case] seemed to make some pretty impressive looking burns with very few errors. [Errors meaning PI errors and/or PIF failures - NOT errors meaning info that you can't read back from the DVD].
I hope this helps you out,