Don't have the Dialogue amp, but I own a Prologue One and a Cayin A88T. The Cayin is a superb integrated with marvelous sound. And, it has a remote and the ability to switch from triode to ultralinear on the fly. If those features are important to you, go with the Cayin. Otherwise I think it's a toss up soundwise.
Primaluna Dialog Two Integrated Amp vs Cayin A-88T
I am going to put together a tube system around one of these integrated amps. I'm wondering if anyone here has compared the two amps. They are about the same price, the Primaluna is rated at 38 watts per channel, the Cayin is at 45 watts. They both use KT-88 tubes. I haven't selected speakers yet, but I am leaning towards Harbeth 7es-3. Any comments/opinions would be appreciated.