We have netsight 6.3 and a mixture of X450 (G1), X460 (G1) X440 G2. Archive, image upgrade, monitoring works fine for G1 gear. I am having issues with image upgrade on 440 g2 from Inventory Manager. It says unknown image binary family.
Thanks
XMC 8.3 works really well with some 1000 switches for one of my customers. They have a mix with X450e being the oldest and X870 being the newest switches. In between those models you find G1's and G2's of more or less all sorts. A lot has changed from NS 6.3 and for the most part it's for the better I think. I don't think you'll be able to keep your network maps though. They were lost in some upgrade step for us. Open a TAC case for this if you really neeeeed your layouts in the maps to be converted into the new format.