Longines makes excellent watches. They use ETA movements, which is owned by the Swatch Group; the parent company of Omega. I would not hesitate to purchase one. Omega is considered a step up from Longines. I would just buy which ever one you like more; do not worry about which is better, as they are both respected brands.
I agree. While I don't own a Longines, I think they are a good value in the world of watches. While Omega is a step up in terms of the finishing and movement, I think it should depend on which style you prefer. Good luck choosing!