Just wondering if anyone can tell me if I can visit my better half, in the U.S. during the K-1 process?

All you can do is try but keep in mind you might get turned back. Good luck

I have visited twice since we filed. I told them I was staying with a friend and I brought proof of ties to the UK but there is not guarantee they will let you in. I thought it was worth the risk of being turned away. The first time I was asked a lot of questions but the second time I arrived at the back of the immigration queue towards the end of the day and they wanted to shut the booth so I got through pretty quickly.

I visited my fiance numerous times while our I-129F was being processed without any problems. I entered the US by car, not plane. I was asked for proof of ties to Canada, such as mortgage/lease documents, my most recent pay stub, etc.

When asked the purpose of my trip, I told them it was to visit my boyfriend, and then I was asked the length of my trip. They once asked me if I had heard of the K-1 Visa, and I told them we were awaiting approval and I was just having a visit with my fiance in the meantime.

Good luck.

You can give it a shot but it is not garunteed that you will get in. Many people however where able to get in,in the past.
If you do decide to go make sure you take enough ties with you from your country such as contracts and and and.
A friend of mine got rejected at the port of entry,she had an interview with them for 3 hours,they asked for her emailpassword and let her fly home right after that.
She said the experience was not very nice.
But this of course does not happen to everybody,if you want to do it give it a shot.