I'm not that experienced with all of this stuff yet but here is my take:

It depends on whether you are looking at short or long term.  If you are talking about short term, then go with whatever you think will gain the most profit in your set time period. Obviously nobody really knows for sure what is going to go up or down in these markets over a short term period.  If you think that ETH is in a position to have a greater rise than BTC based on your research and intuition, then you should make the trade. 

If you are talking about long term, you need to think about which you see has having more growth potential in the future.  BTC and ETH are in some ways competitors, but they aren't aiming to accomplish the same goals.  I think that you should align your portfolio with what you believe has long term viability. I personally don't see BTC or ETH disappearing any time soon, so I think they are both are good bets for the coming years. No idea about which one will perform better though.

I think BTC is established and gaining popularity among everyday people, while ETH is still only known to tech inclined people. That said, I think ETH has a great potential as a decentralized platform, although all the shitcoins being produced on it aren't helpful.

if you can withstand bitcoin until a hard fork happens and then exchange the bitcoin to ETH, we do not know whether the price in the market will go up or down so for now do nothing and save your bitcoin. just wait a little longer to redeem btc to another coin and all will be stable again

Ethereum seems to be struggling to decide if it wasn't to stay above or below $300 right now. For the past month or so Ethereum was almost a carbon copy of Bitcoins price chart, only scaled down. The past few days this has decoupled a little bit as Bitcoin was climbing by hundreds towards its all time high Ethereum was actually going down slightly. Now that Bitcoin is pulling back a little Ethereum is also going down.

It seems that there is no correlation at all anymore so it may not be a good time to get into Ethereum right now until the bitcoin fork happens. As has been mentioned, interest in Bitcoin is now at a high because of the potential for free BTG coins due to the fork.