Well, as a polearm enthusiast, I can answer you a few things.
First, the Swiss Halberd is an awesome weapon, if you know it's limits. You use it wisely, since it's a supportive type polearm, it's not the best choice to go 1v1 on people, but it's not impossible.
This weapon has it's own limits, obviously, it has only two attacks, the stab, and an overhead strike.
Are you sure you want to go this way? If yes, you have my respect.
Against shielders:
Common shielders will come to you with those big ass round shields (Huscarl), or other stuff, and it'll be hard to break them, or to keep them at bay. But if you use the Swiss, you can always use your length advantage against them, just learn it, how far is the optimal range, to hit someone with an overhead, it will help you.
So, what you have to do is simple, but not simple: Try to keep them away, why you sneak in overhead strikes.
This way you deal great damage to shields, since the Swiss Halberd has a bonus against shields, it's bad-ass.
Trouble will start, when they get close. You have to do fast turning manouvers while doing an overhead attack.
If you manage to do it, it can land a hit on their unprotected backs!
Your stab attack is a bit harder to use up close, you have to learn the close-range (lolstab) technique, it's not that hard.
First, Look down with your weapon while prepared to stab. And while releasing it, lead it to your target! This combined with good footwork, will surprise your enemy!
Always heirloom weapons first.
Consider upkeep prices, can you pay for all your stuff, especially Light M&P? I use the normal M&P (blue one), and it's a pain in the ass when it breaks.
If you like your looks, and are happy with your weapon, why change it? Master it!
PS: Feinting skills and good blocking are necessary. Especially for this type of weapon. You can't just spam away, it's forcing you to play in a block-counterattack style. Learn on dueling servers, both Native, and cRPG ones to master these, if you can't pull them off.