RSI thanks for pointing me to page 11. In case others are interested now or in the future, here's what it says about the 007 too:
Pump Selection
The Taco 009 is a medium flow, high head pressure pump that requires an adequate amount of pressure on the outlet side to prevent the motor from overloading.
The Taco 007 is a medium to high flow, low head pressure pump. In a very low-resistance system (e.g., short length of supply and return lines, only a flat plate heat exchanger, etc.), the 007 pump may need to be mounted lower near the base of the furnace to prevent cavitation at high water temperatures.
My supply/return run sweeps out of the boiler (man that was a pain), goes 24 ft, three elbows before the thermostatic valve, a wye strainer, 40-plate Hx, then back on the same route. About 30 ft each way. I was thinking this could be considered a short length of supply and return and only a flat plate Hx. This is why I thought the 007 sounded like a better fit per the manual. I didn't read the manual before I bought the 1450, should have, but trusted the dealer to set me up properly.
Still trying to figure out why the 009 was chosen. Must be for the lower flow. The load on the DHW side of the hx is fairly low I suppose, house is very well insulated and combined with the 800sf radiant slab I don't require too many BTU's compared to other houses.
Anyway I'm leaning toward the Grundfos. One I get it running I'll report back on how it works with my system.