If I'm not wrong...the soft one is slightly longer so it contains a bit more storage space.
And Bill switches are easily done with the soft TT too.
I have always gone with the hard ones because I have heard from many people that the soft ones don't 'release' bills as smoothly and quickly as the hard ones do (i.e. the harder plastic is smoother with less friction).
I do several special bill switches (two that are big on the market right now) that require the bill to move VERY quickly out of and into the TT... and one requires the bill to be 'force-wedged' into the TT (the rim acts to bend the bill on the force). On one of the effects, the creator of the effect actually states that the hard TT is better for this reason.
Do you feel that this could be accomplished with the soft?
Because personally, I hate that stupid shine that comes with use on the hard ones. (I use a dish-scrub pad to dull the TT, but the shine comes back after 3 or 4 days in my pocket).
and concerning the shine not being noticeable with proper use...
humbug... there are many effects that call for the TT to be shown in a direct point in order to establish crystal clear emptyness... and the shine is noticable in that moment.