In one of my recent games: DA (painful) my freighters were bringing in over 3000BC which was about three times my tax income. I had no econ starbases nor did I have the Galactic Privateer.

The freighters are anchored to the planet they were built on. I wish it was the planet they last came from instead. I also wish I could specify the the path the freighter will take as well (to avoid hotspots) even if it were the same path I used to get to the planet in the first place. With the trade route in place, movement slows down to 1 square per turn. I only noticed recently that the freighter begins its trade route from the anchor planet, not the planet you sent it to. I was at war, established a trade route on the other side of the galaxy and on the next turn the freighter emerged from my anchor planet and was blown away by the AI that was attacking the planet. Scratch one trade route.

It can take a long time to get a freighter to the planet you want. What I have done in the past has been to take one of my survey ships (which are all over the galaxy) that happens to be near the planet I want, send it to that planet and upgrade it to a freighter.

Another thing I've done is build a few extra freighters and park them near some AI planets after my trade routes are maxed out. The cost to maintain is nil. Should one of my trade routes be wiped out, I unpark one of the freighters and I'm back in business the next turn.

I am just curious: Has everyone that does not find value in trade routes researched down the trade tree to get all the bonuses?

I've never found much use for trade routes (though I like the extra cash when someone does form one) since I usually run a self-sufficient empire and don't trade my precious resources with the cannon fodder that temporarily occupies my backyard.