If i had gotten the 1400 first, I probably would never have gotten the 1000. the 1400, as you have found, can use 1/4, 8mm and 1/2 bits. that is one reson i got it after I already had the 1000. They are both great routers with very much the same feel and control methods. Since i got the 1000 first, I found a need for a larger router that would take 1/2" bits. Don't take my joshing for the reason for your own expansion.
i like the methods for adjusting the 1400 to be easier than on the 1000, but I imagine the newer 1010 is also easier. I like the feel of the 1000 as it is considerably lighter weight.
both machines do have much the same feel to them and both are more comfortable (to me) to operate free hand without the guidebar. The controls are easier than any of my other routers, especially the switches. The PC's (older models like 8-10 yrs old) are impossible as far as switch location.
you asked about light weight routers. Yes, the 1010 is lighter weight than the 1400 by quite a bit, but you may be thinking of pin routers when you asked the question. Pin routers are much smaller and have their own place in any shop. i do not have any of them. I have a couple of projects coming up where I have been thinking about a pin router but will give them a try with the OF 1000 first.
With all of these replies, I think i have covered all the bases I can cover.
Have fun
Tinker