Valkyrie Profile 2 has mixed feelings, according to my experience. Most of my friends loved it and so did I, but some disliked it.
IMO the game is the best looking game PS2 has, and that alone should be the reason enough to give it a shot. It has a lot of characters, and I mean a lot, probably more than you'll ever use, but it's done pretty well since most of those characters are spirits which you can level up then "release" and get a cool useful item instead, while your regular characters are about as numerous as they are in other RPGs.
Plot is ok, in the beginning it's not explained very well, but as you go deeper into the game and towards the end it gets a lot better and things start falling in place.
The combat is bloody awesome, it's so savage and beautiful at the same time. Lots of different enemies, lots of bosses, crapload of items... The number of abilities, attacks, special abilities, special attacks... It's greater than most of the RPGs I've ever played.
The bad things I've heard people complain about (my friends), were mainly concerning the plot (initial plot) which is just blurry rather than bad, as well as difficulty at times (which can be overcome by a little grind and then returning). Potential issues could be reaching secret chests since some of them require some tricky jumping and some brain usage.
I never played Persona, but I definitely plan to, since people have said a lot about the series, comparing it to FF's quality all the time.
Either way, if I were you I'd go for both of these. :P