lukesdad said:To get back to the op the main difference between the 2 disiciplines as I see it and may have a bearing on what you decide are;
TT 100% race of truth as some call it.
RR More brain power, and the ability to race with sudden injections of pace.
Friends (now in 60's/70's) used to time trial and road race:
He beat her road racing
She beat him time trialling
His explanation:
On a TT he got bored, started planning holidays etc and lost focus on the effort
In a RR he had the better tactical nous
that is much the same as your comment