Can I give an example?

One of my coins is QTUM, It's gotten good reviews from the popular youtubers and holds it's price pretty well during the dips and has stayed in the top 20 on coinmarket cap for months, overall it seems like a good project, maybe one holding out for long term. However one poster in this thread pointed out that they don't have a working app yet as per this thread https://bitcointalk.org/index.php?topic=2243157 this begins to put their capacity to deliver into doubt.

Now, I've seen one coin called Neblio and have been watching it since it was below $1 and again they don't have a working product but like QTUM have a good team, they are new and are apparently are delivering ahead of schedule. In a short space of time it has gone to $5, those are excellent gains and so my question is should I of dumped QTUM for Neblio? Or should I have increased my portfolio (if I could just about afford to lose) and bought Neblio and still kept QTUM?

I see these scenarios all the time and wonder what is the best strategy and in the above example I missed out on a lot of money because I stuck to the plan and was too cautious.