I chose the NE 346XP because I feel it's significantly stronger than the others with only a muffler mod. I did not run mine before modding the muffler. I have not run the original 346XP.
You mean stronger in the cut, if so, not the ones I got. My 5100 is a tad faster in the cut than my 346xp, not by much mind you. I ran both em 10-15 cuts each and used a stop watch and the 5100 inched away from the 346 everytime. The 346xp was new at the time and the Dolmar had alittle more run time on it. The 346xp may well catch that 5100 after break in, they are very close in power. Note too my 5100 is as out the box. My 346xp has had the muffler changed to the old type without all the restrictions. I was using these in wood much bigger than they were intended for. Both 18inch bars were buried beyond the tip and the 5100 came out the bottom first each time but they they are so close to me its not worth worrieing about. To say one is really stronger in the cut than the other is an overstatement because they are so close in power.
They are both stronger runners than my old 026 but the flip side is the 026 has provided me with about 12 years now of trouble free service and has cut lord knows how much wood. When the other two do the same I'll be as fond of them as I am my 026 now. Its gonna take alot of cutting to see if a single ring saw will outlast a two ring saw, I seriouly doult it but time will tell. I'm curious as well to see if a saw running 14,000-14,500 rpms will last like a saw running 12,500-13,000, that too I seriously doult. I'll give my results in about 12-15 years from now,LOL
I will say this about the 346xp, its a joy to use. For limbing its perfecto, small, light and easy to handle, explosive which is great for zipping limbs. Thats one area it has the 5100 beat and on par with the 026. The 026 and 346 both handle better than the 5100 but cut wise in bigger wood, not twigs, the 5100 is the 50cc to beat.