I think I can speak to this. Many moons ago I flew an FH1100. It was a nice helicopter and I have followed its history from the beginning. During the original LOH competition, the Army test pilots did like the handling and speed of the OH6, but the Army brass favored the Hiller as they had a long and good relationship with the company since 1950. Hiller was so confident of a win that he sold the company to Fairchild Aircraft, who assumed they were about to get an order for 3,000 helicopters.
The Hiller has always looked basically the same from the beginning. However the Bell has gone through quite a change. Look at this picture from 1962.
It sure is a compact little devil. You see the basics of the drivetrain are already there: the TT strap main rotor (with soon-to-be deleted stabilizer bar!), the big t/r driveshaft and the t/r hub. It is odd that Bell didn't think much of vertical stabilizers back then. And it looks like it might even have sliding rear doors. You don't have to squint much to see the 206 to come.
The original LOH competition was "won" by two companys, Bell and Hiller. Hughes forced his way in and made it a 3-way flyoff. We understand that Hughes won the contest by dubious methods, mainly offering the aircraft at a loss. When the Army ordered the second batch of around 600 helicopters, Hughes tried to pull a fast one and raised the price. This angered the Army, which reopened the LOH competition. Frustrated and disillusioned, Fairchild decided to not submit the FH1100. By this time Bell had redesigned the OH4 which is another story itself!
Had it been submitted and won, the FH1100 still would of compared unfavorably to the OH6, like the OH58A did. Although it flew well, it did not have a tilted mast like the 206. I liked it for lift work or spraying, but it was bad for long cross countrys. As far as autorotation went I felt it was between a 47 and a 206. Not quite as much intertia as a 206, probably needed heavier tip weights.
The FH1100 was no more vulnerable to mast bumping than the 206 was. Back then pilots were flying Bell 47s and Hiller 12s, they were not used to the higher 120+ mph speeds that the FH and 206 flew at.
Over the years, various companys have tried to restart the FH1100 production line, none has succeeded so far. Too bad IMHO it was a pretty good helicopter. Thanks for the stroll down memory lane.