Indeed. I said questionable. Go to any review of the release of Android 2.2 and you can see the performance improvements that are pretty much universal across devices. This simply conflates the two and implies something that isn't true.
With 2.2 the Streak is competitive with other 2.2 devices. There is no surprise there, given that it runs essentially the same processor as the Nexus One.
The Dell Streak is actually a QSD 8650, while the Nexus One runs the QSD 8250. Both phones run on the Qualcomm dual-core architecture: arm9/arm11, with one processor dedicated to linux "apps" and one dedicated to the "amss", aka modem software stack.
I have both devices sitting on my desk here, so I ran a comparison. As I suspected, they are close. Also note that the Dell Streak's resolution is much higher and I'm not sure how/if the benchmark takes that into account:
Linpack (higher is better):
Nexus One: 32.94 MFLOPS
Streak 2.2: 33.373 MFLOPS
CaffeineMark (higher is better):
Nexus One: 5587 (rank 124)
Streak 2.2: 5738 (rank 109)
An3dbench (no idea how scores stack up):
Nexus One: 4746, Fill rate = 10MP/s, Game level FPS = 24.87
Streak 2.2: 4495, Fill rate = 17.65 MP/s, Game level FPS = 32.26
With 2.2 the Streak is competitive with other 2.2 devices. There is no surprise there, given that it runs essentially the same processor as the Nexus One.