Torn between two

Is it the love of the work or is it because you are familiar with it?
I am in a dilemma...to stay in the current division or go back to the job that I'd done for the past 6 years. I thought that I had enough of MICE, maybe I needed new environment and new experiences, because I was getting sick of all the haggling, and begging, and negotiating, and the last minute requests, and the lack of manpower.
I thought that I needed to get away from all that..
But then I discovered that I was good at my old job...
I am still tuned in to the updates, industry people giving updates, old contacts been calling me, I think I missed the old division...and perhaps the action.
I am currently serving in Research Division. The new division did not have clear direction and purpose, we were neglected from attention and care of the bosses...so it feels as if me and the others have no purpose working in the division. Research is a different ballgame altogether, it's more technical what with the programme that we need to learn like SPSS, or forecasting. It is exciting in a different way, but maybe I was not fully trained for that.
I must confess that I am getting sluggish in the PR department, not getting as much action as I was used to. Not that I missed all the late night dinners & functions. My life is more calm and organized now, which is not a bad thing. But more than ever, I think I cared about doing the job properly, and I am confident that I can be better at MICE than I was before.
The only problem is, I have not been inducted into MYCEB yet, and I am sort of doing illegal job for my former boss, ZHS. My immediate boss is vehemently against the idea of me going to MYCEB because she didn't want her staff to be pinched, after a few others were done the same.
Admin Division was not much help, delaying the transfer for months when a formal request have already been made. Instead they offer the position to people who were not willing to join MYCEB, and it also has become a dumping ground for officers who just came back from overseas and had nowhere else to go. MYCEB needs experienced people in MICE to go because the work is just piling up. Anyhow, maybe I am in a dilemma ethically, but as far as feelings go, I can't wait to go to MYCEB!