Retul may seem new but it is not really that new. It has been around as Crucial Innovations and Retul is just the bike fitting aspect and use of the technology.
It all comes down to the fitter. Review the fitter’s credentials. Credentials outweigh the tools used. A good fitter will not brag about his or her tools but be able to confidently review their credentials with you.
Retul can be useful in the right hands. A good fitter does not need Retul but a good bike fit using Retul still needs a good fitter.
But keep in mind a good bike fit will cost you some money. Rarely will you find a GOOD fit under $200. However you can find plenty of good fits between $200 and $350.