335 is $100 cheaper, 0.4 lb lighter, more streamlined, and gives a bit more reach ( air cleaner/ carb in a better place) 020T is very well built, reliable, great power, very well balanced. I ran 020S's for many years.
I own 3 old 335's, and one new one. Got one of first on west coast four years ago. Most of the earlier problems are solved. But the new saws seem a bit shy on power. I'm shortly sending my new one up to get it Walkerized for ~$80 US. This should add 20-30% more power. Two of my old saws cut well, close to an 020T in power. The third was a demon with at least 10% more power than any 020T I compared it too. I may replace the ring and maybe the piston to get it back in top form. The cylinder look fine and it has no air leaks that I am aware of, but the power and compression have dropped off. It's had a bunch of hard use.
A lot of people were turned off by all the early problems. Don't listen to them, I feel most of them were not patient and persistent enough.
Walker's will hop one up for you and deliver it for about $450!!
Then you can tell your 020T buddies that they own a dog!! And prove it.
The Echo 3000 (~200$)and 3400 (~260$) are nice, light saws. Both lack the rpm and sheer power of the other two, and won't stand up too as much abuse nor last as long.
Here's a link to current ebay auction!!:
http://cgi.ebay.com/aw-cgi/eBayISAP...&showTutorial=0&ed=1013822118&indexURL=0&rd=1
hope this helps