4Game

I think we all have this bad experience in dota2 late game every now and then. Imagine 40+ mins and you are playing Spectre. You got your 6 slots and the same with enemy cores. Enemy pos4 and 5 all got glimmer cape and one of their cores being heros like slark/riki. So in order to kill their key heros during team fight you need to give up one item slot to carry dust/gem/sentry ward, otherwise you will be fooled around like a monkey in late game by their supports (imagine a 40+ mins pos4 shadow shaman shackle and hex you for 10s! I know people might argue that your fellow support heros would carry dust/ward in late game, but a lot of times they risk their lives to place wards or cast dust during team fights.). Basically you have to give up a 5000+ golds item just to counter invisibility. Sometimes when carrying aegis, apart from dust and boots, you only have 3 item slots left. Imagine a core hero with 3 items after 40+ mins! (Nowadays a lot of core heros have to give up the slot for boots in late game and most of them feel like crawling like a turtle. Sometimes they would rather give aegis to a non-important teammate just for the item slot.) I am totally fine with force staff, eul or ghost scepter. But invisibility is just so overpowered especially in late game.

As a player with 4000+ mmr and more than 10 yrs of dota, the above experience does not sound fun for a lot of dota2 players. Here are my suggestions:

1. Just like neutral item slot, assign designated slot(s) for dust/wards, I think League is doing this way. For gem, we could introduce the same mechanism like the scepter buff, you could buy a scroll to upgrade gem to gem buff, and you lose both the gem and buff once the hero dies.
2. If dota2 developers feel like the first method is too much change for UI for the moment, here is a more subtle change: remove the CD when moving up items from backpack slots if the normal item slot is empty(since the slot would got empty after heros used their dust/ward) or if the moved-up item is dust/ward.
3. We could also consider similar solution for boots slot and aiges slot.

Dota2 has gone through many big changes to make it more fun and less clumsy in certain ways. For example the introduction of backpack slots, nertral items and individual couriers, stacking of observer&sentry wards, to name a few. I think the above suggestion has its points as well.