hi, I am not a zcash expert but I have been reviewing it lately along with several other similar ones. zero, to my knowledge is the same as zcash with some of the math changed. I don't think zcash uses master nodes. zcoin is not comparable other than the fact that it achieves privacy. the mechanism is not the same. zcoin uses libzcoin which is not zksnarks. so it's an entirely different setup and it therefor not comparable in the same way. zcoin to my knowledge uses masternodes for the verifications of 'minted zcoin' .. the zcoin minting process requires the coin in the local wallet to be 'burned' then replaced by the network with coins from pool of unused. zksnarks have a trusted setup which uses locally stored parameters to generate (z) payments. there is no need for master nodes here, the payments are generated locally from the coins in the wallet and transmitted at the same time. in other words, the extraneous process that zcoin requires to have new coins has been removed and replaced with a setup that requires trust in the integrity and modalities of the initial creators of zcash.

zencash seems to be the closest comparable coin however in my mind it is not comparable at all. they have changed the core and added the master nodes and also added a "finders fee" of 8.5% which is deducted from the miners share. only a portion of this (3.5% if I properly recall) is used to incentivize the master nodes function.. in reality the "creators" of zencash are pocketing the other 5% or spending it as the see fit in the name of zencash development. so you can see the "business model" is entirely different than that of a free coin like this (zero currency) . there is no coin comparable in my opinion because the closest relative is zcash which also claims 20% from the miners for a period of initial mining years, the exact time I cannot recall. It is really absurd to think there is any comparison because zero is simply the best. once everyone figures this out it will be even better..

"bigger coins" like zencash and zcoin it is a funny comparison when zero is better in every way (in my opinion and I am entitled I have been researching) .. zencash and zcoin have marketing. that is all. I compiled zcoin from source and it has so many warnings I almost wanted to vomit. I am surprised libzerocoin even compiled at all! to be worse I lost 50 coins on one of their old wallets "burning them" and never did receive the transaction back. However, to team zcoin's integrity, they did help me recover the coin but it was more luck than anything.

we can see all of the big coins started high up the charts because of their marketing and ICOs and that will also be what is the problems with them because they have created a set of expectations and in some situations received vast amounts of funding to produce the goods. most of the ICOs will not produced much of what they have promised, or someone else will do it better and first, for far less money.

the world is changing. look to the quality, not the marketing.

PS, when you say "ZenCash goes here even one step further and not only hides the sender and recipient of a transfer but also the amount which was sent." that is not an entirely accurate statement. Zencash had nothing to do with the Zk-Snarks development, they simply forked Zcash. Credit where credit is due. Team Zcash's zk-snarks is what protects the transaction and that includes the amount and the coins ID. In other words all forks of Zcash inherit this property unless they are somehow broken.

PPS: Let's not forget that Zcash has a $250,000 security audit done on their code. Changing the core to add masternodes (unless I am wrong and it is already a part of zcash) voids all guarantees that the audit means ANYTHING to the forked coin. The more near the code is to the original Zcash code which was audited is the more realistically sane coin to trust your money to. much else seems like a gamble to me. believe this when I say I have seen core bugs in the code that some of these clever devs have modified and it is scary.

From you are list beside NXS which of them can you say are eligible to be bought at this time and ave a great probabilities at profit( any new suggestions)?h

in case you mean "back" not pack then no you are wrong, the ICOs are not backed by anything. you just buy ETH tokens and in rare cases use your bitcoins to invest in them. that doesn't mean they are backing anything!

anything that comes out at first doesn't have any value. then it gains value based on its supply and the demand for that supply.
airdrop is just one of many methods of distributing that supply.

most coins use mining, some use airdrops, some use rewards in POS, and possibly other ways too.

Also, you have to consider that about 30% of bytes will be added into circulation, diluting the existing 'shares'. Therefore, I expect the GByte price to take about a 20% hit straight after the airdrop, could be more, could be less. This expected price drop will likely completely offset your 20% of additional GBytes received, at least at the time of the drop. Of course one can speculate about the price increasing afterwards......

It's a matter of the risk you're willing to take. By only linking your BTC balance you're not risking anything, simply collect the free Byteball coins and keep  all your BTC.
By exchanging BTC for GBytes you can gain much more for a higher risk (price of GBytes could go down, then you're sitting on a loss).

There's more information about the effect of linking vs. buying in our wiki: https://wiki.byteball.org/airdrop