I've been playing this game for a long time, and nothing beat the feeling I got when I earned a new champion after playing hard and winning games to earn IP. However, in the BE system, it feels like it takes longer to earn champions - even though the math proves otherwise.
To get every champion in the game you need 570,900 Blue Essence. If you play enough to level up once per day (which is attainable), you will get an average of 1000 blue essence a day (level up + first win bonus), which comes out to 570.9 days, or 1.564 years. However that's with hard level grinding. Most people get a level once every 2 or 3 days, which comes out to 333-500 BE a day. @ 333 BE a day, you need to play for 1,714 days, or 4.697 years.
@ 500 a day, you need to play for 1,141.8 days, or about 3.128 years.
With the old system, you'd be getting about 50 IP per win, and assuming you achieve 10 wins a day, that comes out to 500 a day. However, most people are not achieving 10 wins a day. With an average winrate of 50% and 10 games a day, that comes to 5 wins a day, or 250 IP per day. This would be (on average) double the amount of time it would take to earn a champion compared to the Blue Essence System, and this isn't even accounting for champion shards, which provide an average discount of 40%. If you only buy champions through champion shards, this comes to about 1.25 years of play. This however does not account for disenchanting shards you own, which speeds up the process even faster.
So, yes, the Blue Essence system is faster - however it certainly doesn't feel like it. The system provides you with a chunk of Blue Essence each time you level up, with a minimal amount given once a day for a win. This system is faster, yet feels slower because you're not seeing your gains until you hit that Level Up benchmark. This causes the system to feel sluggish and unrewarding, even if you are purchasing at a faster rate. In short, Riot, please change the system or add a new feature to make the system feel as it should, because twice the speed should not feel like twice the time.
The system could even be revamped - remove Champion Shards from the Hextech Chests and put the Blue Essence back into the games in each win. For example, it takes 3072 EXP to level up from 110 to 111. This means it will require about 15.36 games (assuming you get 200 EXP per game) to level up.
If the Blue Essence system was changed to incorporate BE per win instead of champion shards, it would come out to about 62 (rounded) Blue Essence per game. This, combined with the Capsules you get for leveling up, will make the system feel both more rewarding and faster compared to the current Blue Essence system.
In case you wanted to keep the system at it's current speed but make it feel more rewarding, remove the "Disenchant" option from Champion Shards that you don't own. This would allow the system to stay at about the same speed, but feel much much more rewarding, especially for players that play a good amount of games per day.
So, Riot, please - consider revamping the Blue Essence system. I don't know how many people I can speak for, but I certainly have met a fair few both on the Boards and in-game that prefer getting rewards per win over exclusively rewards per level.