I'd suggest that the quality of the training you receive is more important than type of equipment. To convert to glass is easy but going the other way round is more difficult. This is because with a full glass display (PFD & ND) and a decent flight director you become a very lazy bunny as you tend not to keep up your scan as you would with steam clocks. Also, don't forget that there are glass cockpits and glass cockpits, each is different and learning on one type will not neccesarily confer any advantages on "learning" another.