In general (there are exceptions) the rb26dett is a more reliable engine than the vg30dett. Also, it is much easier to make more power in a RB. The VG has problems with devoloping and holding in heat. I have seen many a melted knock sensor from the engine getting hot and the heat having no where to go. With the V6, there is also added complexity of have two of many parts. Also the intake manifold makes it very hard to get at things and its a pain to get off. For drag puposes, I would say the RB is a much better choice for ease of working on, power potential, and stength of parts. It was made as a race engine form the start so it should hold up better in harsh conditions.