Titleist Professional 90 vs. Top Flite vs. "Balata" balls?

Urethane is the new balata, only far more durable.  I am guessing that the ProV1 is the closest Ttitleist ball to the Professional 90.
 

Comparable spin, much better distance.  The new solid cores are much more resilient than the old liquid cores surrounded by rubber bands, and they spin less off the driver as well.  If they weren't better, pros would still be using the older technology.  Even today's 'rock' balls are pretty darn good.

No.  The ProV1's and ProV1x's are the next incarnation of your Titleist Professionals.  The DT's are hard distance balls.

I may be wrong on this, but I'm pretty sure the "90" in the Tour Professional 90 was referring to the compression of the ball.  There was a Tour Professional 100 as well, and the DT Wound had a 90, 100 and 110.  That being said, the ProV1 or ProV1x may not be what you're looking for as they require a lot more swing speed (maybe 105-110mph plus) to get good compression on them (i.e. they are a tour compression ball).

 

I wouldn't say don't try them, because they may work great for you (and maybe you do have a fast swing speed as well).  But based on another post I saw of your's (I think it was you asking about a newer used driver, vs. an old cheap one... sorry if I got that wrong though) which you mentioned hitting the 3W 200yds, I was taking a guess your swing speed isn't over 100mph.  That being said, here are some other balls you may also want to consider.... Titleist NXT Tour S, Titleist Velocity, Callaway HEX Chrome, Nike PD Soft.

You haven't played in 10 years?  I hadn't played in 25.  The advances in golf ball construction are simply amazing.  Like you, back then you had the choice of the "tour" balls, Balata covered but would barely last a few holes before the cover got damaged or the Surlyn covered rocks of the day, which was just about everything else.

 

My suggestion would either be pick a selection up from a yard/garage sale or go golf ball picking the next time you're out and try a variety of them.  There are quite a few budget golf balls, under $25 a dozen, that will provide very nice results. 

I also took about a decade break from golf...

Upon my return, the differences in the golf ball was by and far the most significant advancement. I was a 3.8 handicap using Balatas and the Professional 100. There isn't much in common with today's golf balls and the ones made 10 to 20 years ago although you could probably match putter feel to the professional 90.

I would suggest buying any ball labeled "soft", like the Nike. I currently use the Titleist Pro 1Vx and am amazed by its performance, although I hear it is just like some other cheaper ball callaway makes?