I love those Tualatin Celerons. They rocked!!! The history of the Celeron CPU has had high and low points.
LOW
Original Celeron 266/300MHz with no L2 cache - decent overclocker but weak performance.
HIGH
Celeron 300a-533 with 128k full speed L2 cache - lower speed grades had some awesome overclockers and full speed cache meant great performance versus P2/P3 SECC/SECC2 with ½ speed 512k cache.
MEDIUM
Celeron 533a-1.1 - Coppermine version had some awesome overclockers. I've had a 533a that did 800 at default voltage. Few friends had 566@850. I had a few 800@1066. One friend had a 900@1200. Sure, a bit weak versus P3, but a good bang for the buck (like the slut down the street).
HIGH
Celeron 1.0a-1.4 with 256k cache - Tualatins were awesome. The slower ones, again, were the better overclockers. They had the same amount of cache as the regular P3 chips, only bested by the "server" P3 chips with 512k cache. Basically, if the P4 wasn't around at so much higher clock speeds (let alone AMD chips), the Tualatin Celeron would have almost been the chip of choice.
LOW
Celeron 1.7-1.8 - These Willamette chips could overclock a bit, but were considered pretty weak in performance. Kinda like the original no-cache chips.
MEDIUM-LOW
Celeron 2.0-2.8 - The Northwood version is considered pretty weak, but the lower clock ones could overclock like champs. This made the "not as bad as" the Willamette chips.
MEDIUM ???
Celeron D - What will the Prescott version bring us? I've already heard that it doesn't suffer as much performance deficit versus P4 Prescott as the Northwood Celeron suffered against the P4 Northwood. It has already been shown to overclock decent. Kinda remeniscent of the Coppermine Celeron versus P3. It is slower enough that it doesn't cut into the sales of the higher end chip, yet it has just enough oomph to not be totally outclassed.