Hi,
The NEO4 modchip is not a BAD chip, its just has not got the same spec of a Messiah. The NEO4 was released first and then soon after the Messiah which has a better spec.
It dpends what you want from your modchip, i know 2 peeps that have NEO4's and very happy with them and i also know a few peeps who have Messiahs and very pleased with them.
Its your choice m8.
Dal