I found that in the first version the rules were very heavily in favor of the polish to the point were it became quite off putting. It was extremely har to win over a polish army with any other army. Have they fixed some of this in the second edition?
I read that fairly often, which makes me wonder a bit because I primarily played Polish-Lithuanian commonwealth in 1st ed and got my ass handed to me more often than not

What forces did you play and or meet?
There have certainly been changes to how the game plays now, you no longer have a dozen units (some as small as 2 bases of cavalry). Instead you have 3-5 blocks on the Skirmish level and 3-7 units on the Task Force level of the game. I think that change and how army lists are now more balanced rather than historically accurate based on 17th century OoB.
I also think that the game has changed up some of the recon effects and scenario effects that come into play when you have two uneven armies clashing. In 1st edition you could basically win by having a bare bones force that received A TON of game effects that basically made your opponents life a living hell. Combined with that pretty much universally hated "river crossing scenario" (that is no longer in the game) there were a lot of circumstances that made the balancing of the game a bit off.
My personal opinion is that the Swedes were, and still are, a hard hitting force that can pick apart many opponents with their disciplined reiter units. I have not played enough games to give you a 100% accurate review on the game balancing, but I can see that the recon and scenario effects make much less impact now. The match-ups I have played so far have been Sweden-Denmark, Sweden- PLC and PLC-Cossacks. Will try to get some games with Brandenburg vs Sweden this week.
The second edition is definitely more "gamey" in its approach to rules and gameplay than 1st edition and a lot of the national and unit based special rules have been rewritten and are imo less impactful.
PS.
The tournament in Wilanow Warsaw Poland saw the same player win multiple tournaments several years in a row with different and on paper "weak" lists, none of them PLC. He specialized on fielding tiny forces and using the terrain, recon and scenario effects in his favor. I don't think he would be able to pull off the same things here in 2ned edition due to how units and force compositions have changed radically.