Is there any altcoin with improvements in blockchain download time? Let me introduce my idea.

Given:


sizeof( Blockchain ) = 16Gb
Downloading of one avi film 16GB from the pirate bay ( 5mb/s ) = 2-3 hours
Downloading of bitcoin's blockchain ( 5mb/s ) = 2-3 days
One day = 6 * 24 = 144 blocks.
Drag - cryptography. 


Task:


Accelerate boot of fresh client to the torrent speed. Similar to Bootstrap.




As I can see, downloading of blockchain is the same hard as mining, because there is every time recalculation of hash, comparing, checking of signs, etc...

What if client will only download this 144 blocks for a day and one super block with 144 hashs of the last valid blocks, thereafter only compare current wallet's addresses with addresses in this 144 blocks without any calculation of its hash.

Is there any alt-coin with such accelerator? 


E.g. this super blocks might be archived into another ultra-block for a month. Than we have similar to sha(sha(text)) cascade shield against bruteforce attack. 

Downloading of blockchain should takes at max the same time as downloading of 16GB avi from the pirate bay. Say, 5mb/s internet channel + p2p / 16 Gb = 2, may be 3 hours ( in the no peers case ), but I spent 2 - 3 days, and I see that this is no internet speed reason, it is CPU + harddisk very very hard job.
Your premise is wrong. The work required to download and validate the blockchain has nothing at all to do with the work required to mine it.

As far as the block hash goes, validating it requires just one hash while mining the block requires quintillions of hash calculations.

Validating the block also requires computing the hashes of the Merkle tree but the main work is validating ECDSA signatures. Your method is not going to help with that.

(On a meta note, it's rude to offer "improvements" when you don't understand well enough what currently exists.)