I'm posting this for those who might google a review of these levers in the future.
They are on my '85 Trek 400 "restomod" roadie, that formerly had ST3400 9-speed levers on it. I was sick of the thumb buttons and now Shimano has the 3500 series out with the "proper" shifter setup.
I got them for a song online (Niagra Cycle) and was pleasantly surprised after I unpacked them. They are essentially a 9-speed version of 10-speed 5600 105 levers. The hoods are the same, the lever shape is the same, the shift/brake action is very similar. Trickledown has been VERY good to Sora.
I'm a fan of the hood shape, as the 3400 hoods are narrower and less ergonomic than the 105-style 3500 hoods. Definitely a comfort upgrade. The levers are painted (not anodized), so I don't know how long the finish will hold up. They look fantastic now--especially with black bar tape.
Braking action (leverage/clamping) is improved over the 3400 levers, mostly due to the longer 105-style lever of the 3500. It's still not stellar on this bike, but I think that's due to the Tektro R536 calipers that I'm running for the 27" to 700c conversion on this bike. The 5600 105 levers with 6500 Ultegra calipers on my other bike clamp like the Dickens.
No issues with tuning--they set right up in a snap.
Sure, the Soras don't have the clout of a higher end group, but they work fantastically. A great choice for a 9-speed backup bike.
Hope this helps some people in the future.