"It is perceived by some, that the Spanish witnesses do not earn as much as their English counterparts, have less education (particularly if raised in the truth) and are more oriented to religion in general."
I can see this as true, however, the Spanish-speaking JW's are generally very hard workers and will stop at nothing to take advantage of the relatively good economy here in the States to provide for their family as best they can. Just take a glance at the Spanish meeting parking lot... materialism is a big issue in the Spanish congregations, perhaps even more so than in English. There are less pursuing higher education, but more working longer hours.