Hi filter,
I've played a few TRB1005's and was impressed with all of them. They were very playable and the onboard EQs give a lot of tonal possibilities.
I'm not sure why the TRB1004 is not listed on the site.
An inch difference in scale length will definitely give a difference in tone. I'm not great at explaining the difference verbally, but you could get an idea of the difference if you compare two recordings of Primus' "Greet the Sacred Cow." The one on the Anti-Pop album is played with a 32" scale bass and the live version on YouTube is played with a 36" scale bass. Listen to the differences in tone...
The difference between a 34" and a 35" will be less marked than between a 32" and 36" or course, but at least you'll get an idea.