I would highly recommend two things here,

1. Most important - keep placing your investment in DASH by whatever means you can

2. If you wnat to keep it in PIVX, ensure that you buy in LOW and once the price goes up, sell and move back with the profites into DASH.

My reasonings for the above is plain and simple, Dash is going places where no crypto has gone before, think about it - from the time bitcoin came out and all the other ALT coins started to get released, did any one of them solve bitcoins major issues or even the crypto issues in general, the answer is simply no.. Only when Darkcoin / DASH emerged that this started to happen, all other crypto's went in the opposite direction.

Here are some major points to stay with DASH:

1. Evoution release - https://www.dash.org/evolution/ (think Paypal but better)
2. They are the first to implement DAPI (Decentralised API)
3. They are the first with a Governence system
4. First to release Masternode Tier and Incentives for full nodes
5. First to develop Instant Send (Instant Transactions)
6. First to release consensus on Block size change within 24 hours (Bitcoin dev/community and still split on this)
7. They will be the first to have accounts similar to ISA Savings where users who hold get rewards
8. Merchants will also be incenstivised
9. They have the best Marketing
10. They fund themseleves through their own coin - How cool is that ??

The list goes on and on...and you can really see a pattern here, where they were the 'first' to do things.

At the end of the day the choice is yours but i would really make up your mind quickly before the price starts to shoot up really fast towards the middle and end of year!