I think it's reasonable to start looking for new gear when the confidence bubble around the old racquets has truly burst. Even if the frames are fine, there's no arguing with the reality of our noggins believing that these racquets are somehow wrong for us. That's a serious distraction that needs to be overcome, often by moving on. Then again...
I went through a similar progression when I replaced my old 6.1 Classics some years ago. I also tried a pair of LM Radicals, but they were also light and unstable for me. Making decent spin with those was more of a challenge, too. I've settled in with the Volkl C10 for a few years now, but it took a while for me to get dialed in with the new racquets - it may also take a while for you with that YT Radical Pro.
I've always liked racquets with 9-10 pts. HL balance and my Volkls have lead on their handles to give me the familiar handling that comes with that familiar balance. You mentioned that your Radical Pro is sluggish for you, so my advice is to tune your frame along the same lines (lead tape under your grip or overgrip) so that you get better handling. It may not work, but it just might be the simple solution that helps you to turn that racquet loose.
We don't discuss racquet balance around here as much as other spec's, but I've found that it's the key to my best fit with any frame I use. Even if the flex or static weight isn't exactly what I prefer, the right balance can help me to feel much more at home with any racquet I try.