As far as I understand, traffic will bring some benefits only if you have already some contention. Shaping will then prioritize traffic as per your rules.
I'm pretty sure you will get, assuming there no network contention, benefit from ads removal.
Then debate is perhaps more to discuss about ads removal implementation ;)
Tweaking DNS is one option.
Relying on features like Squid + Squidguqrd is another way, better from my standpoint. Do not expect throughput improvement when adding Squid in the middle.
Benefit of cache is very little nowadays, especially if you perform tests with one single user, mainly because of the dynamic aspect of Web and the use of HTTPS almost everywhere.
But I believe you will get more granularity and better (to me) control with Squidguard than DNS.