Me as a lfr hater, will answer this. Though I will not say anything about removing lfr or anything.
For me, perfect itemization would be:
First tier:
Lfr ilvl = heroic dungeon item lvl
Normal = +10 ilvl
Heroic = +10 ilvl
Mythic = +10 ilvl
(that's 15 or more ilvl saved in the first tier alone)
Second tier:
Mythic dungeons will be introduced again as catchup
Lfr = first tier normal ilvl
Mythic dungeons = first tier heroic ilvl
Normal = first tier mythic ilvl
Heroic = +10 ilvl
Mythic = +10 ilvl
Third tier:
Lfr = normal second tier
New set of dungeons (mythic only) = second tier heroic
Normal = mythic second tier
Heroic = +10 ilvl
Mythic = +10 ilvl
Like this ilvls increase by only 20 between each tier.
Lfr will always be the worst way to catch up, which is really important to me, as it still serves as tourist mode and mythic Raiders will always be able to start a new tier in heroic difficulty.
Now in WoD, we have an ilvl gap between mythic brf and mythic HFC of up to 40!