I always like to hear from fellow nids players. I have been running nids for about 5 years, in many different combination's and will give you my 2 cents.
In 5th edition your worst enemy are vehicles and losing HTH. Expect every opponent to have at least 6 vehicles and build you army to address that. Sorry to say that loading up on masses of gaunts has not proved beneficial for me. In tourny play, I run one 8 strong unit of termagaunts without number and that is all the gaunts I care to take. The rest of my troops are genestealers. Ask yourself what is your goal. "I want to out shoot people" - your an alien race that wants to eat planets, you don't out shoot people! "I want to jump on them and eat their face" - now you're talking! So why would you load up on tons of gaunts who will lose in HTH and have to take armor saves (6+). It's a nice fantasy, but nids are outclassed in the horde and shooting arena (until next codex).
My advice: Focus on the nids strengths - Monsterous creatures and genestealers. People reading this will be squirming right now - know why - Because these two units DO work.
Nids are a fun army to play, so ultimately it's about what would be fun for you. Good luck and happy eating!