Between me & my brother we have a 1800 GW , R1200RT & a 07 LT.
The RT is a different bike to the other two though often compared with them.
In my opinion, the LT rules by far when it comes riding position (the saddle feel) & has a much nicer cornering ability (I also can't tell you how much I appreciate the adjustable wind shield once you really get to know how to use it).
However, the Goldwing proved a much more reliable machine.
Last year my brother drove from Kuwait to Paris (approx. 5000 miles in total) with 8 other bikers, it included 2 LTs & 4 GWs & other bikes.
None of the Hondas burped once ( in fact, to date) but with the LT's, One lost its shaft seal (while in Germany as it happens
) & the other one developed a mild noise in the engine by the time the trip had ended.
Japanese quality is way more superior (& less costly to maintain) & I say this having used many different makes of both cars & bikes but going back to the GW & LT, If you want the "Bike feel", the LT is the bike. GW feels much more "car'ish".
As for wight, they are both heavy & skill & experience is needed to handle either. Once you got the good feel, you'll never worry about the bulk.