I agree. Of course, if you don't like it for some reason, you can always go back to 5.3.
For me, the biggest advantage was the iView remote, which I really like. But since you're using a universal remote that will emulate either a HomeWorX or iView remote, that's not a big advantage for you. But the iView remote does have a few extra buttons, a couple of which (Aspect and PVR) you may find useful.
The second big advantage may or may not apply to you. If you have channels without a -1 subchannel (or if you've deleted or skipped the -1), the iView firmware lets you tune it by just entering a channel number. You don't get "Invalid Channel" if you leave off the -2 (or whatever the lowest subchannel is).
Finally, there's more info in the infobox, transparency for the menus, and a 12-hour time option. Those aren't "biggies" but are kind of nice.
There is one teensy-weensy downside: iView firmware doesn't have HomeWorX's "Power On/Off" scheduling function. But I've never heard of anyone who used that anyway.