I have had both for awhile and I'm a PvE player. The Ice breaker is high impact/high recoil. With the ammo regen it is ideal for taking on bosses or enemies with a large health pool. P&T is a low impact/low recoil rifle. You can put a lot of precision shots down range fast. Make it good for taking out a group of small enemies or one major. With its cloak ability you can alway begin the engagement without being suppressed by enemy fire. Also, with the cloak ability and being a Titan main I can get to downed allies and pop my shield without risking a wipe. Both are extremely useful in the correct situation and play style.