So I've been testing my new i5, with the same mobo (the z97m aniversary). While at stock and voltage at auto, it maxxed at 1.14v, idling at 0.84v. Temps with occt were 56ºc on the hottest core.
Bumped speed to 4ghz (100 mhz+), same auto voltage. Same 1.14v max, 0.84v idle. Same temps.
Bumped to 4.2ghz, but lowered voltage to 1.123v, override mode. max temp 47ºc. With a cm evo 212 push/pull fans at 100% (do not have control over them, 3 pin only). Fully stable so far in everything I'm throwing at him.
My former cpu, the pentium, to reach 4.2ghz would need 1.350-1.375v, and even then it would not be fully stable, having to downgrade sometimes to 4.1ghz and 1.32v. Max temps there were 70s, but never above 80ºc.
What a world of a difference this is, Witcher 3 stuttered even though I had "60" fps, now it's smooth as hell. With the g3258 I had no issues while gaming + streaming, but the stream would stutter. Not anymore.
And I'm still going slow, but hell, these temps and these voltages are giving me hope that I'll be able to reach 4.5-4-6ghz easily and fully stable.
If nothing bad happens to the cpu, I'm good for the next 4-5-6 years, not needing to do an upgrade (unless technology goes forward in a pace unlike we've seen in the last 5 years).
Hell, I tried crysis 3, some options on very high others on high(for testing), I'm always locked at 60 fps :| I couldn't play it on the g3258.
My advice on someone that is thinking on buying the pentium for gaming, if you can wait a little while and save up for an i5, you will save more in the end and be rewarded with an awesome cpu that will last you a long time (if not abused). Like an i5 2500k, they are still around even though they were released in 2011 and they are still viable cpus.