Do they introduce extra sponginess?

Not so I’ve noticed.

Good. Eyeing up some ones with barrel adjusters in from SJS cycles for my drop-bar/mini V commuter.

I have those on my Caadx they’ve been fine..

Groovy.

Some of them split/explode eventually, only giving you a 2 second warning. Spongy brakes to all but uncontrollable hurtle in 2 seconds isn’t fun.

Specifically the flexible ones?

Yes.
They eventually wear out/fatigue/split.

I switched back to the proper shimano ones and did some trimming/pipe bending to get them right. They were still on the bike when it was dismantled and sold off in pieces.

SJS sell rigid adjustable pipes too, in case you hadn’t spotted them.

Yes, but only 90 degree ones, and I think I might need more of an angle.

Already ordered though, so we’ll see, I’ll keep an eye on it.

When I converted to drops I put barrel adjusters in the brake cables, cos I didn’t think of it before the build and that’s what I had lying around. Should’ve searched for adjustable noodles first, this is really going to improve the bike.