I have been on both sides of multiple ticklers, giving and receiving and for me it is a different kind of experience. As tickler, it just wasn't nearly as much fun because it's hard to get feed back as to what is tickling her and what isn't. For example, if I'm tickling the armpits and someone else is tickling the feet and suddenly her laughter changes, was it something I did or what the other guy did? To me that is very important.
On the flip side, when I have been tickled by multiple women, it was not really more intense for me, just different. For me, it's not like three women make the tickling three times more intense, in fact I think a single woman can get me going as much if not more than multiple ticklers.
I think trying multiple ticklers can be fun and different, but not necessarily better. But it's worth a try!
For me, one on one is better. I prefer the intimacy of the situation, it just seems more personal. Not just someone tickling a piece of meat without any emotional connection. Having that connection makes the experience much more enjoyable and fulfilling.