This might be a bit late but did you clear your flash cache after putting the new gear in your bag? One of the quirks of this game is that flash player will keep the stats for your old clubs and you may not get the full benefit from new ones unless you clear the cache. If you go here and either delete all sites or find media5.wgt.com in the list and just delete that. It's advisable to do this after every equipment change and every WGT update, if not more often.
My first club upgrade didn't do much for my game either but they were way worse clubs that you now have. I haven't tried the G20's as I was already using R11 gear when they came out but I hear great things about them.
When you say you dropped 2 strokes, I assume you mean your average has come down 2 shots since getting those clubs? That's not bad depending how many ranked rounds you've played with them.
Looking at your score history and stats I would say you need to work on parts of your game a bit, your driving stats are fine but greens in regulation is well down and average distance to pin is a bit high. Sorry if I sound condescending, that's not my intention, I just don't want you to quit because things are going bad, with practice and a good read through the forums you can improve a hell of a lot.
You're right that this is a great game, it really is. It has it's faults but of all the online games I've tried and in some cases sunk a fair bit of money into, this one has kept me interested by far the longest.
It sounds cheesy but keep at it, you haven't been here that long so don't expect too much.