I spent 3 weeks with one of the Bali Hai girls from opposite Christin's back in July. She pulled me in off the street, sex was not offered on site, and she later told me that full service is not allowed at Bali Hai. I think the girls could get fired for it. But it should be easy enough to get a happy ending there though, whether male, female or as a couple. I don't think it has been mentioned yet in the thread that you can pay a fine to Bali Hai to keep the girl with you, just like with the bar girls. It was 600 baht/day. And her schedule suited me just fine: 1pm to 12am. Plenty of time to go out for a little while after work, and sleep in in the morning. And free time for myself during the afternoons and evenings, but she could still stay with me during the day if we wanted.
I had met several other girls during the first week, including getting a massage at one of the other shops in question, and it was great, but in the end I preferred the GFE with the Bali Hai girl more than going with a different bar girl every night or a quickie with the other massage girls. But I had the luxury of time that many short term vacationers don't. And enough travel experience to take it for what it is, and make sure that she knew that even though it was my first time in Thailand that I am not a sucker, and to call her out on anything that seemed off, even as innocuous as her saying she felt like eating pizza that night. I'm still waiting for the sick buffalo email, though.
Walking past the other girl did get a bit uncomfortable. She would give me mean looks and make faces when we walked by, and made sure I didn't forget her!