try looking around for a little and see other people asking the same question each time price rises. the answer for bitcoin is always the same, it is a good investment but it is not risk free.
as for Aug 1 we don't know what will happen, and large dip is not "general thought" of investors, you have been reading some FUD.
as for your main question look at this way:
bitcoin:
has real demand.
people invest in it as a store of value, as a strong technology that has been working perfectly without any problems for 8 years.
it has a solid developing team. the code is reviewed and it is bug free.
hackers have been trying to hack bitcoin, attack the network, ... for 8 freaking years and they have never succeeded.
people are also buying bitcoin because it has real world usage as a currency. you can buy almost anything with it these days. there are thousands of merchants accepting it. there are 200,000 merchants in Japan alone.
countries have either embraced bitcoin as a legal method of payment or are thinking about it
ethereum
it is centralized, don't expect any change that community wants but expect any change that the developers feel like it. hint: DAO roll back, Difficulty bomb, Change of POW,...
has no real demand apart from speculators, idiots who are forced to buy ETH tokens to invest that in ICOs
it has not been around for long, it has lots of bugs and exploits.
it has a terrible scaling issue which has led to $1 transaction fees even with fast (15 second) blocks and no backlog like bitcoin has!!!
running a full node is extremely hard and much more expensive than bitcoin and that leads to more centralization and lack of nodes as time goes by.
it is not even a currency! it is a platform for smart contracts and it is not doing it well enough a better platform can easily replace it. some even believe RSK will do that soon.
in terms of fees, i will prefer both, because the fee of sending bitcoin is being almost the same in US as ethereum. since altcoins are less popular, their fee are less than what bitcoin will be and normally faster in transaction.
buying reliable altcoins are currently better than bitcoin as they are often pumped really fast, which gives you a chance to be a rich within a very short period.
I think it is good time to buy ETC because it has same features like ETH and when ETH will go POS miners will shift towards ETC mining that can rise its price dramatically. On the other hand, bitcoin is always good for long term holding.
yup, bitcoin is the most traded cryptocurrency, as the popularity raises, higher value you are holding.