I consider Bitcoin as the storage layer. Yes, it can be used as a transaction layer. But there are many coins that offer other lower transaction fees and are faster. So what? The real question is which one of the Transaction Layer currency coins will emerge after this current run up of Bitcoin. For this I consider Litecoin, Vertcoin, Groestlcoin, Verge, and NAV.
As a disclaimer, I am not going to focus too much on the Lightning Network or Atomic swaps. These features are powerful, but I am waiting for them to becomes mainstream. I am going to focus on the existing differentiators.
Litecoin
This is the most established of the alternative currency coins. This has the tremendous advantage of Charlie Lee's leadership. People keep predicting a breakout, and the Technical Analysis shows a movement upwards. But what is the motivation to invest in LTC versus some of the other coins? It is fast, and it's dependable. There are privacy aspects in development, but nothing concrete has been announced. Perhaps if LTC announces some key privacy features this will be a catalyst for upwards momentum.
Vertcoin
Vertcoin has a great community, and one just has to read the reddit articles to see the tremendous involvement of the community. A significant difference between Litecoin and Vertcoin is the ASIC resistance that Vertcoin demonstrates. In the online forum discussions, evaluating the ins and outs of the ASIC resistance have been discussed in detail. This is another strength of the VTC community; the awareness of what ASIC resistance brings to the table. It appears that Vertcoin community and developers are committed to keeping the coin ASIC resistant, and have the technology to back it up. Now with stealth addresses coming and the low fees of transactions, VTC is very attractive. If one looks at the long term, the stability of being ASIC resistance is a real advantage. It means reduced potential of forking and undue influence from the mining community as to what is going on with Bitcoin right now.
Groestlcoin
The funny name apart, this coin does indeed have significant technology. GRS has several wallets that will run on mobile devices (note the world several) and have been ahead on the tech curve for a long time. The main difference between GRS and VTC at this point is that the VTC community is more active and engaged imho. Some from the GRS community would disagree but that is the way I see it. One main differentiator for this coin is that it cannot be sent to a wrong address ! This is a great feature for this coin as people would adopt it mainstream. I will be watching this coin, it has an AMA with the developers coming out and it will be interesting to see where this coin goes.
Verge
Although the circulating supply is high, I see room for this coin to grow. The mobile wallet and the Wraith protocol are going to make it easy to send Either private or public transactions. That is a great feature to have both options. The Wraith protocol is the main differentiator for this project, as well as the very fast settlement times of 5 seconds. I personally do not have a position in this coin, but am closely looking at it. I'm watching it because I think in terms of being something that you would use to pay for your starbucks coffee to buy something at home depot, this coin seems like it will be able to do it. The privacy features is very attractive to many.
NAV
I think NAV is a great project, and I am waiting it for it to explode. The anonymous dApps that have been talked about just are not here yet, but the privacy feature and interaction with Changelly is great. The new NavPay wallet looks great. I think a big differentiator with Nav is that you can buy it directly! This is not available in the other coins, where you must go through another route such as an exchange from BTC.
Summary and Conclusions
I sell all these coins having a bright future. I am breaking down currency coins into two further categories. One is a primary currency function with stability, and the other is currency with privacy. What I would have to say at this point is that Vertcoin has a strong community and a pretty clear vision with excellent technology, and Verge seems to have a robust privacy solution with options of either private or public send and solid wallets (tough choice here with respect to Nav.) Thus VTC and Verge are my picks for currency coins, but all of these could do well. I am just trying to look at which ones will have the most potential coming out of the Segwit 2X fork. Even with the large circulating supply of Verge, I see tremendous gains that can be made, and for VTC, I see the vision and community creating a very stable currency coin that is attractive for a long time.
Legal Disclaimer
I am not a financial advisor, and this is not financial advice. Do your own research before making any investment decision.