On the most recent episode, you guys were mentioning how you'd rather play Trails of Cold Steel 2/3 on PS3/4 instead of Vita. I feel the opposite--I played ToCS 1 on Vita and could barely put it down. It helps that that game basically checks every box for me to enjoy it, but I feel as though having a portable option for good RPGs nowadays feels more rare than I'd like it to. In general, if an RPG goes multiplatform and has a Vita release, that's the version I will buy. I love that little system, despite Sony obviously not feeling the same way.
I'm of a similar mentality, at least when it comes to PS3 and Vita. There's something amazing about having a full-fledged console-quality game that you can take with you on the go and play whenever you want. I used to lug a console with me when visiting my dad; now, I just bring the Vita and work on my portable backlog. It's great!
I'll be getting CSII on Vita, partly because I have the first game on Vita but mostly because that's where I'd prefer to play it. I have so many console games to get through already, and I can only play them when I'm home; having CSII on Vita means I can play it at work, when traveling, visiting family, sick in bed, etc.
The performance issues on Vita are certainly not ideal, but the first Cold Steel had noticeable slow down in certain areas too, so I don't think it'll bother me that much. Honestly, what I find most annoying about the first game's performance on Vita is that it doesn't run at native resolution, which makes things a little blurry at times.
As for Cold Steel III, we'll have to see what the graphics look like on PS4 versus Vita (assuming it even comes out on Vita; last I heard, Falcom is kind of up in the air about that). If it's a significant improvement, I'll probably get it on PS4 first and then get the Vita version later. If not, I may just get the Vita version.