Well, I did practice with Kanetsuka sensei. He used be known for his hard, even rough style of Aikido. It changed after his illness - the form of the technique did not change dramatically, it still looked like Yoshinkan Aikido, but his techniques felt different. I have never experienced Ikeda's Aikido - for me it felt more like Tamura sensei's Aikido.
Your comments are very interesting. Everyone remarked on the changes in KS's aikido when he became seriously ill in the mid-1980s (for those who don't know, he had an inoperable nasopharyngeal tumour) - he carried on teaching and practising even when he was shockingly emaciated and physically weak. At that time he was strongly influenced by his recent close contact with Sekiya Sensei and also from the visits of Yamaguchi Sensei to the UK at the time, both of whom I think helped him to develop a substantially softer and much less effortful aikido.
All the same, I have come to the conclusion over the years that his aikido is still largely based on that of his first teacher, Gozo Shioda. Note that I don't say "Yoshinkan", since the Yoshinkai syllabus to me looks rather more rigid and codified than what I see Shioda teaching and demonstrating himself. I haven't experienced any senior Yoshinkai teachers in person, but I think Kanetsuka's emphasis on training in postural and structural stability, his ultra-compact body movement and his direct and instant connection with uke are much more similar to what I see in Shioda (and also as I have heard it described by Robert Mustard and others) than in most teachers in the Yamaguchi line.
Having said that, though, and as I mentioned earlier, there is a perhaps surprising convergence with Ikeda Sensei's aikido. For instance, there is a nice clip of the latter here
, which demonstration I have seen Kanetsuka Sensei do many times, and which I understand is intended to illustrate connection without tai-sabaki (to get back to the topic of this thread).