i use a 192t, but then i live in australia where a 192 is about $600 and a 200t is $1500. If i lived in the states and could get a new 200t for $600 or less brand new, I'd definitely buy it. even worn out second hand 200t's go for $800~$900 here.
Having said that, the 192t isn't a bad saw. I used to use 200t's in new zealand when all i did was forestry pruning for furniture grade pine plantations. We got paid $1/tree, and had to remove every branch within a 2metre range, sometimes 15~20 branches. I'd start that saw up in the morning, redline it to warm it up then run it at redline all day and it would never skip a beat. 150~200 trees a day on big days. Most of those saws would get used 2~3 years at that rate, then sold for $800.
I dont do much tree work now, and what i do is generally from the ground. my 192t gets occasional in tree use (2 or 3 times a year?) for tricky trees that need to be taken down piece by piece, but my core business is building houses, not cutting down trees. I run a 12" bar on it, and it runs just fine. The 200t only has maybe 20% more power, what you really pay for is the durability (steel dogs vs plastic etc). If you need bigger than a 12" bar, then you need bigger than a small saw, go for a 310 ;-)
Increasingly, i find myself carrying that little 192t in the trunk of my car. Its such a handy little saw, and it takes up no space at all. I store it with a sharp chain and a full tank of gas and bar oil. When i bought it, i thought of it as a real dinky little plastic saw that i might use for a bit of pruning but it always starts up real easy, and it gets through some big stuff if you arent hard on it. I'd rate it every bit as good as chinese made rear handled saws you buy at hardware stores up to 40cc, It's saved the day more than a few times with firewood, helping out a friend, pruning and felling smaller trees.
My only other saw is an 044 though, and that thing is just too big to carry up a tree. if you've got the cash, get a 200t and you wont regret it. You might not use it very often for in tree pruning, but if your only other saw is biggun, you might use it a lot more than what you thought for little jobs. You'll get a lot of years of good service out of it (I'd never sell mine) but even if you decide to get rid of it, you'll get a good price.
Shaun