Just my opinion, I have a Valentine 1 and I've found it to be incredibly accurate. Also, once you buy one, you'll never buy another due to obsolescence. Valentine has an upgrade program. If it can be upgraded to the latest technology, they'll upgrade your unit and send it back to you. If the new technology does not fit in the current case and requires a new case, they'll upgrade your old unit by taking it back and sending you the new unit.
I bought mine on ebay, used. I made sure the serial number was intact and verified the upgrade price. I got a deal on the "old" unit cheap, and sent it in for the upgrade. I got back a brand new unit for less than the new units cost at the time. I've since only needed to upgrade once. Turnaround time on upgrades is fast.