We have 642 PowerPorts in the store where I work, but I have not shot one, nor have I found a customer who has shot one to give me an opinion. So take that into consideration when you read what I write next.
Don't buy it. I have shot other PowerPorts including the 686 6" PP and the 629 3" "Carry Comp" and then compared them to solid barrel counterparts (686 6" no port and 629 3" "Trail Boss" no port). The port is supposed to reduce muzzle flip, and in my opinion it does not do that to a significant degree. The port is not an effective compensator as found on "race guns". Those have multiple (usually progressively bigger) holes and usually have extra weight at the muzzle.
Add to that several reasons not to have a ported barrel on a close-up personal defense gun: 1. it's louder (not too big a deal IMO) 2. you're redirecting muzzle flash right up into your sight picture (bad for low light/no light shooting) 3. you're venting hot gases and particles out yet another direction on a revolver. Typical revolvers vent gases/particles out the muzzle and out the b-c gap to the left and right. Add a port and now your venting up, too. At the range, not really a big problem. In a fight, up close and personal possibly at contact distance with your assailant, potentially a big problem especially if the gun goes off near your face. In fact, if you do an "Arizona Rescue", it WILL go into your face.
My advice is worth what you paid for it, but if you ask me (which you did), I'd go with a bigger grip and/or lighter bullet as suggested above or get an all steel J or all of the above. At the very least, see if you can "try before you buy" at a range that has one for rent or from another shooter that has one already.
Good luck.