Hi John,
I'm sure Tek's 7904/7A19/7B90 introduction was sweet revenge.
HP switched to battling for the crown in Portables next but Tek was on solid ground starting with the first 1nSec risetime 485 portable. Tek was continuous stream of newer products with continuously improving specs at steadily lower prices and that held HP off there as well.
Tek's lead in portable spectrum analyzers (the 490 series) was considerable but HP kept nipping at Tek's heels in that market.
Even today what is left of Tek is still battling with HP to see who has the best scope. In the end the marketplace wins because this kind of healthy competition results in breakthroughs and instruments with more capability for the customers.
Dennis