I've fished with them all. Vex's, Marcum's, Humminbird's, X67's....
X67 still gets my vote as long as it is set up correctly.
Run a split screen zoom. One side is the full water column and the other is the depth you are targeting.
Don't let anyone that is advocating a flasher give you the "real-time feedback" big steaming pile of BS. If your screen is scrolling from right to left, the right side of the screen is instant. If it takes 6 seconds to scroll across the screen, you get 6 seconds of history to watch your jigging pattern and pick out the preference of the fish for the day.
The one thing the Vex has on the X67 is the low power mode. If you are fishing in extremely thick vegetation or a crib, the X67 has too much screen clutter to see fish and/or your jig. Another thing the Vex's will have is dependability. They really can take a lot of bouncing and banging around that would destroy other locators.
If it's worth anything, I used to be paid to sell Vex's and tell customers why they were the best. Then I would go home and fish with a X67.