Where to start...

I was thinking of bowling in the PBA pattern or Sport shot over the summer but I have a few questions for those of you that have bowled these.  I saw a few good bowlers struggle on THS after having bowled these in the summer.  Did any of you experience the same thing?  If all houses will have THS conditions, including state and city tournaments, what benefit will I get out of bowling in one of these leagues?  Spare shooting?  I am already a pretty good spare shooter, so how will shooting spares on PBA or Sport conditions help me if I will bowl nothing but THS conditions(except once a year USBC nationals)?  

My average has increased 5-7 pins starting 3/4 into the league until now(1 week left).  The reason for this is because I started learning how to play THS conditions.  
In the start of the league I would play a "tighter" line which meant less pin action and more over/under results.  Since then I have increased my rev rate and played the adult bumper THS houses have.  I have had less over/under because if i swing it too far, I have enough revs to bring it back.  Same thing if I tug it in the oil, I have enough revs to carry lite hits.  

So the questions I have are, "What benefits do I get by paying extra to bowl these tougher conditions if ALL Winter leagues are THS conditions?"  Spare shooting on THS conditions are easier and my ball reactions are predictable unlike Sport conditions, "so how will shooting spares on Sport conditions benefit me?"  Accuracy does play a part but I don't throw plastic at all spares, just at the 10 pin.  Spare shooting on THS and Sport is just a matter of a different line and understanding the reaction.  Since I will bowl PBA/Sport conditions but once a year, is there any real reason to bowl it during the summer versus just bowling a regular THS league?

It sounds a little like you've answered your own question.

In my opinion there's only really one reason for bowling on a "sport shot" or PBA experience, and that's if you want the challenge. There's no doubt that bowling on these patterns requires more accuracy and consistency than bowling on a house pattern.
The reason I bowl on more difficult patterns is that I don't just want to be able to bowl well in one place, or on one condition. I want to be able to score well anywhere, and that requires experience and good technique. If all I did was bowl on my home centres house pattern, my technique would change and adapt to the environment, bringing in bad habits which enable me to score in one place, at the expense of technique that will allow me to score well no any condition.

I enjoy bowling, and I want to see how good I can be, I think that's a good enough reason to bowl on these more difficult conditions.

That aside, I disagree with others claims that you can be "too accurate" I don't think there's such a thing. If you're very accurate and can play anywhere on a lane, then your consistency shouldn't be a handicap.

If you're looking for a tangible benefit, the more experience you have on difficult patterns, the more you'll be able to adapt when you go to the USBC nationals. You seem to have already recognised that bowling on THS requires a specific approach, bowling the sport shot just needs something a little different again.
--------------------
Reporting from England