Ian,
I, too, played powerstroke in Links from the day it was introduced until it began to cause problems with my wrist and I had to switch to RTS. Like you I found it to be the most realistic swing within the game. However, I was well aware that it was used by a minority of Linksters compared to 3C and RTS, due to its' inherent difficulty. In JNPG I now use the horizontal version of the RTS-M swing which is essentially the equivalent to powerstroke. Though you don't have to click/release the mouse button at the snap point in JNPG, its' difficulty is balanced with the lack of a meter to use to guage power and the need for proper tempo.
As to power equating to more distance, this is true in real life but ONLY IF YOU HIT THE BALL PROPERLY to reduce spin. Ballooning is caused by excessive spin - a result of hitting down on the ball with too much power. This is what seems to have been modelled in JNPG for the longer irons/woods. Too much power causes too much spin and the ball balloons and ends up flying a shorter distance. Why would they do that? In real life reducing spin on long irons/woods is a combination of a flatter/shallower swing path at contact, shaft stiffness and ball hardness. Since swing path is already coded into the game if one wants to reduce ballooning one would have to use a combination of a shaft of appropriate flexibility/stiffness paired with a ball of the appropriate softness/hardness. This is exactly what you will be able to do within JNPG with the release of shafts of varying stiffness and balls of varying hardness, as Mike explained in a post some time ago. It will be up to you, the player, to determine which combo gives you the results you desire.
Personally, I quite like using the ballooning effect as a means to drop a wood/hybrid/long iron onto a green with little rollout when the distance would otherwise indicate using a higher club that is more likely to roll off the back of the green or not roll enough to get on to the green. Risk vs Reward.
Intel i5-4570 cpu @ 3.2 GHz, ASUS Z74-K mb, ASUS GeForce GTX 960 gpu, 16 GB ram, 2 x SSD drives, Windows 10 64 bit
Steam name: sound_flier