Installed Harken
Big Boat this summer. Love it. You can sort of see it in the attached photo.
Replaced the OEM Schaeffer 3:1 purchase with Harken BB 4:1 purchase and can now adjust traveller even with main loaded.
Harken's mounting is the simplest. Do not have to align & drill holes to match, bolt heads slide into bottom of track and then fit into existing holes in mount risers.
Sizing is right on the cusp between mid range & big boat models. Used Garhauer blocks on the main sheet. Garhauer's traveller is cheaper by ~$200 but need exact alignment for drilling mounting holes and it is also bulkier. Had bent to 3-9/16" depth along a 61-1/4" chord.
Adjustment lines lead aft a little different location than OEM Schaefer which is a dodger consideration.