The MS 440 was discontinued for sale in the USA in 2008. You cannot buy a new one unless you stumble on a dealer who has a new one in stock.
The MS 441 weighs the same as the MS 460. Depending on where you live, The MS 441 is $75.00 less than and MS 460 of the same configuration (flush handle bar vs wrap handle bar). The MS 441 is a more advanced design of 2-cycle engine. You must re-adjust the carburetor ever time you change elevation by 2,000ft. If you do not, it will run poorly. The new for 2011 MS441 has an automatic adjsuting carburetor which elimates this.
The MS 460 has more power and more torque. If you are dropping timber you will notice the power. if you are cutting firewood and running a 20" bar with a sharp chain, you will not tap into the true torque of the saw.
I own 1 MS 460 and 1 046 and 1 046 Magnum. I use my 046 Magnum when I go and do trail openings in the spring. Some of the trails are at 9,000ft elevation.
I have a almost new Husqvarna 372 in the for sale section in my thread Non California Hand Held Equipment For Sale thread for 30% off list.