Smirker... I didn't make any mods to my Ki5, so I'm playing with it in stock form. At first I experimented with adding lead to 3 and 9, and then just 12 o'clock, but it didn't work for me. I found the racquet to have less control when it was leaded, but that was just my experience. I realize everyone will have different experiences based on their playing style, arm strength, level, etc.
I tried many soft strings and even full natural gut with the Ki5, and though really comfy, for it still lacked the "pop" that I desired . The poly string @ 50lbs was the secret ingredient for me. If you desire a more stable feel, I would give it a try.