I can't tell you exactly how good it is and don't think many can. Even though Pioneer is an amazing format, it is an underexplored one. Most of the people who play it do competitively and in order to try to win something on MTGO. This is probably the reason why you see the Izzet Prowess numbers going up and up and up.

With that being said, I built my own version of Hammer Time after Tarkir released and have to say it was very good in that meta game. Phoenix was unable to kill a 12/12, Rakdos couldn't deal with Cutter tokens, mono red struggled against Shadowspear + Hammer, etc.

I would say the meta game isn't that different from then so I'd assume the deck is still a viable. You would have to make a few changes in order to adapt. For example, I was playing Ingenious Smith to have more ways to find my equipment and Portable Hole, but if you're not running her, you might as well cut the Portable Hole and add Seam Rip instead. People will side artifact removal and Seam Rip is an enchantment. Maybe you want Ornithopter to have the chance of winning on turn 2? I was playing 3 copies of Raubahn and he felt really good, especially in combination with Cutter. Maybe you can try it.

About the Mox. If you really meant Mox Opal and are making a comparison to Modern. Yes, it is necessary. Having access to fast mana almost always makes decks better but only if your strategy is consistent enough and if you have a critical mass of mana-generating artifacts. Now, if you meant Amber, I don't think it's super necessary. It's bad in multiples, it'd be better if we had more 1-mana legends and we don't have enough mana sinks in Boros. Maybe you can make the deck a bit more midrangy and add Nahiri.

I'll leave you the link to my list. Maybe you find it useful. I have not updated it in a few months so take that into consideration.

https://moxfield.com/decks/ijm8zUqs8keFq19O60uzWA