Very good question.
It states somewhere that SL7 is a Steinberg product.
I am considering:
Sound Forge Pro 14 Suite
$250 upgrade price. Valid until June 28, 2020
For me this is a better deal the getting Samplitude Pro X5 Suite with SF13 and SL6/7 for $250.
The Samplitude Pro X5 Suite includes SF13. If it was SF14 I would buy it.