Oh dear...
Well, let's see here.
There are some points that both of these guys have:
- The excitement of participation in battles
- Martial Arts skills, which, I think they are both tied in, which is why I'm listing this here.
Before going on with other character abilities, let's delve into their characteristics. Or at least, try to.
In battles, Goku does not want to fight in any place that are populated right? Zero seems to be quite fine with battling in cities, which would make him less cautious when he just goes around and gets himself thrown into buildings. Well, I mean I can't say much when it comes to settings as an argument point since most of Zero's battles are in space. Just thought that it would be worthy enough to point this out, but... Eh.
I'm going to assume in-character judging from the little dialogue you made.
Then, there's the skill stuff again, I'd argue that Zero does have more on skills and experience since he's fought against people with a greater arsenal of powers. Not only that, he's literally spent years doing nothing but training, which Goku has done as well so it nulls this argument.
Screw this.
Despite their even-ness(?) in physical capabilities and skills and experience, there are also a few other things to factor during their fights.
For one, Zero is not beyond spamming his beams which, as some people have argued, that Goku doesn't really do that often.
Goku still has his IT, which, when it needs to be used,
will be used. Zero has dealt with teleporters before and often, Ultras do have an aura of sorts which should allow Goku to lock on to and send himself there.
While Goku is very versatile in battles, so is Zero. If Goku somehow manages to hide somewhere, Ultras, especially Zero's kind, all have the ability to see through things.
Still, Goku has Solar Flare, which Zero is stupidly not resistant to. He can blind Zero, but often, Ultras can recover from those quicker than most opponents the Z fighters have faced.
What else?
However, in the hax department, Zero dominates. I think. His Mind Manipulation is definitely something to be wary of, and Zero is quite good at handling his psychic powers. But still, he doesn't seem to use these as frequently as his father does. Who, even then, only uses it when he can't transform back to his original form.
So all in all, if we go in-character:
I... Can't really come up with a good final verdict. But let's try: Going with that, both of them would be flying around while trying to mercilessly beat each other down, like usual. Goku might go for his IT at some point, but if Zero can see through that, he can simply improvise and use his sluggers as reflectors that he can use to attack Goku with when he uses IT. So... Tie maybe? But I suppose it all comes down in stamina when the fight goes like this. They both have great stamina reserves, but still limited. But in case his stamina is getting low, Zero can just fly off to outer space and recharge... Which Goku can also do by asking for an emergency Senzu... I think I've cornered myself.
I'll leave the floor to other people.
