Close.
The Aguilar OBP-1 is close to the Tone Pump. The OBP-2 and OBP-3 are different animals.
I totally agree.
The TP is dirty... gritty sounding.
The OBP-2 and OBP-3 are very clean, very crisp. And very powerful... meaning they have a bunch of headroom. You can really crank out the volume before you start peaking, whereas the TonePump will peak much earlier... thus the addition of the trim pot on the unit. Which is what makes the TP worth keeping in my opinion.
Dial a TP in and hit its sweet spot and it'll get you so much closer to the USA NS-2 Haz sound than the OBP could ever attempt. And of course the TP was designed to sound like the Haz... And Aguilar made the OBP for every/any bass manufacturer... so that makes sense.
If you want a clean, crisp sound that really has nothing to do with the traditional Spector sound... the OBP is a great choice.
If you want the dirty-growly low sound that the NS-2 is traditionally known for... keep the TonePump and play with that trim pot until you dial it in to what sounds best for you.
And has 2 negatives recently. See if he'll let you take a look at it maybe?