Thanks a lot for the reply. I like oversize racquets and am currently using the latest version of VCore Pro 104 (yes, that one only available in Japan), also in my bag are Wilson SW102, Dunlop CX200 OS, and old Yamaha 110 sq in racket. I was using Prince Phantom 107G for over 1 year.
I am looking for a little bit more power and spin. Both SW102 and 107G are good in term of power. SW102 just too heavy to swing. 107G is lacking stability for me. VCore Pro 104 is maneuverable due to lower weight but still feels solid and stable. Just my shots are slower and less heavy. Maybe I should play around with string tension before trying the SX600. Since I use Volkl V-Square string, any multi or soft poly in the cross will get cut through really quickly so hybrid probably not an option.
In many ways I'm not the person to be giving advice on oversized rackets because as far as I can recall I've only tried two (an oversized pure drive briefly back when I started playing years ago and then the SW Autograph racket).
Just giving some of my two cents on this, I suspect on paper the Dunlop SX 600 is going provide about as much power and spin as once could expect to handle on court in real match situations. The standard 100 inch version is somewhat of a bomb itself, but it's very much tamed by its extremely high launch angle and spin access, which can possibly counter some of that power. But with the 600, the extra length, the increased head size, the even more open string pattern, and what I assume is still the same frame design it's going to swing mighty fast and it will be super explosive. I have little doubt it will produce more of the kind of shot you want, from the brief bits you're saying, than the vcore pro 104. And the power and spin level of the 600 I imagine would leapfrog that of the SW racket as well (if I remember, the SW racket has a moderately high swing weight, which might be what makes it feel heavy to you, whereas when I checked the 600 it has a very low swing weight and static weight).
Can you demo the SX 600? There's also the Dunlop FX 700, extended length as well, 107 inch head, 23/27/23 mm beam, but even lighter than the SX 600 but looks to have a higher swing weight.
Re strings and tension, remember that tension really only affects the launch angle. So while lowering the tension may feel like your increasing power, largely because the same shot at a lower tension will travel further and higher, you're not actually upping the ball speed. And with strings, yep, in an oversized head and so much space between the strings really only super durable strings are good bets unless you don't mind stringing after each session.