Other than the obvious split grip on the Mojo,  what's the difference. The blanks appear to be the same....I heard Mojo is made in China, perhaps Premiers are made in the US anything else?

All Mojo rods have been made in the US so far.  The cosmetics & split grips are the only real differences between them & the Premier graphite rods.

Whats the difference between Mojo Bass and Premier?

Very little if any.......

Mojo Bass:

* Premium-quality SCII graphite.

* Technique-specific bass series designed and built for superior performance.

* Batson Forecast hard aluminum-oxide guides with double-plated black chrome frames.

* Fuji® ECS reel seat/black hood on casting models.

* Fuji® DPS reel seat/black hoods on spinning models.

* Split-grip/premium-grade cork handle.

* Two coats of Flex Coat slow-cure finish.

* 5-year warranty backed by St. Croix Superstar Service.

* Handcrafted in North America.

Premier:

* Premium-quality SCII graphite.

* Outstanding strength, sensitivity and hook-setting power.

* Finely tuned actions and tapers for superior performance.

* Batson Forecast® hard aluminum-oxide guides with double-plated black chrome frames.

* Flanged SiC top on musky models.

* Fuji® ECS or TCS reel seat/frosted silver hood.

* Premium-grade cork handle.

* Two coats of Flex Coat slow-cure finish.

* 5-year warranty backed by St. Croix Superstar Service.

* Handcrafted in the U.S.A.

The mojos also offer actions not available in the Premiers. There is no 6'8" MXF or 6'9"MLXF, etc. in the Premier line as far as I know. Components are the same though.