Preference to "Larger" over "Smaller"? NO
Preference to "Faster" over "Slower"? USUALLY
We work on the principle of maintaining a "SAFE, ORDERLY & EXPEDITIOUS" flow of traffic. The order of those criteria is not negotiable.
Chances are therefore you will usually find yourself at the back of the queue in a PA31. The fact you are a light twin is in itself enough for an ATCO to subconciously think you are going to be slow, notwithstanding the fact you're flying a fairly sporty aircraft.
Why not advise the controller what speed you can do when you come on frequency? It might help him/her to make a better judgement to which YOU may benefit!
If conditions permit why not request a visual approach? Might help both YOU & the CONTROLLER.
Why not cancel IFR and continue VFR? Join the circuit and fit yourself in, could save you oodles of time / track miles / money etc.
To put it simply - if you don't ask you won't get......
Hope this helps.