Monarch Man,
You wouldn't be the Monarch pilot that refuses to use his full callsign as well, would you? I had to put up with this all the way from MONTY to LAMAT and found it very disconcerting in a very busy session.
Standard RT is there for a reason. When I'm busy, I go back to that standard RT, no embellishments or shortcuts. I also slow down transmissions to aid thinking time etc. Having someone else cutting corners means that I really have to focus on their readback more than most.
Whilst I can see the arguement of you point, I would ask you, as a professional, to stick to the standard RT. It may seem to you to be OK to cut corners at MAN, but if you continue to amend your RT it could get you into trouble elsewhere.
Regards
CF