More grist for the "It's A Fake!" treadmill: this is George Takei interviewed in 2003, quoted directly from the DVD featurette
'Kirk, Spock & Bones: Star Trek's Great Trio' featured on the Season 2 DVD set.
"He's a wonderful actor who created a singular character. No-one could've done Kirk the way Bill did. His energy, and his vitality, and his passion, and his supreme self-confidence. You know, that's Bill. And that's Captain Kirk."
Doesn't sound like a man harboring a 'feud'.

(Of course, something could have soured the milk since then, or perhaps it was just Takei being complimentary about Shatner's acting ability, without actually commenting on his personal opinion about the man himself. But I don't know..... I do still wonder if both men have strung out this 'feud' thing as a mutually beneficial publicity stunt.....)