Preamp Out-Amp In RCA Jumpers for Integrated

Does anyone have any experience with some of the RCA Jumpers for integrated?
Jenna Labs has a set $60 bucks, Cardas a set $80 bucks. I know both would make a big improvement over the wire bar.
My brother replaced U shaped bars between pre and power section in his NAD integrated with Audioquest Python 12" RCA-RCA jumpers. It opened top end and improved clarity.
I use the audioquest jumpers that are only a couple of inches long and got the same results as above. I haven't tried any others.
I have replaced my wire bar with a custom Signal Cable Silver Resolution RCA to get a very good upgrade on overall sound. Cost me $40. Highly recommended.
Dhel - I think my brother's was less than 12" - more like 6" but it was less than $40. Cardass for $80 seems excessive.
This is a REALLY GREAT IDEA - one of the best and simplest tweaks I have ever made. I tried the Audioquest jumpers and they were an improvement over the stock bars, but some custom made silver wire jumpers I am using now are just the cats meow. To test effect without spending money, just replace the stock bars with one of your pairs of interconnects and see if you hear any difference. I think you will.

Here are some commercial choices:

Page 22 of Audioquest retail price book

Most special order interconnect makers will gladly make you a really short set of interconnects.

Or, make your own out of a little bit of silver wire and some quality RCA jacks. Its easy since you only need one lead to the pin on each end.