I have been flying these things since 1997. Initially I too built them without a bypass, but for the past 10 or so years I have only built my jets with bypasses.

I concur whole-heatedly with the previous two guys and will add only the following:

Pro's:

- During a hot start you have far more chance of saving your airframe and may at worst have to replace the bypass.
- During a hot start you only have to direct the fire-X into the intakes and don't run the risk of damaging anything else during the process.
- Jets with a bypass, uses less fuel, I have done the test and proved it - timed, startup to dead stick.

Con's:

- Sometimes I don't get to build a jet I like because I cannot fit a bypass.....too bad, I won't be buying it.

Cheers,

Jan