I wish I could try the Vita app (damn Sony for not having an accounts system on the Vita

)
So far my quick impressions of Ishin are the following:
First off graphically its even better than 5. It looks clearer and sharper with better texturing all round (Yakuza 5 had some terrible textures, most store signs). Oh, and water actually looks like water this time around! Cinematics look fantastic as always and the scenes that use the in game models look better this go around as well. Kiryu especially looks really good and detailed.
Gameplay wise the combat feels a bit more complicated than main line games. I'm still fiddling around with all the different moves and combo's that you can use. The gun especially is pretty fun to use (especially when you use the special ammo). Heat moves seem more varied but I've not managed to pull many off as of yet (I'll have to consult a guide to see which you can use in each stance). The hand to hand combat feels like classic Yakuza, you have your basic combos and grabs and you can pick up weapons from the environments as always.
There aren't many mini games in the demo - you get river fishing - Anyone have any idea how this works? I get to the point where the fish turns red and starts headbutting the lure but I can never catch the damned thing. Just as I got used to Yakuza 5's river fishing they go and change it up again!
And then there is the drunken singing (Kareoke). This bit stars Majima and is probably the highlight of the demo so far, its a blast and might actually beat Majima's singing in Dead Souls.
My big surprise is that there is little to no loading. Shops and resturants are all outside so there are no load times accessing any, and battles have even less load times than in Yakuza 5. You go straight into battles and after the quick ranking screen at the end of the battle you are back on the street.
So the game kind of feels like Kenzan 2.0 at the moment which is certainly no bad thing, I can't wait to get my copies in a couple of the weeks!