4K metal is not a significant difference.
In most cases, the range difference is not important, as either both SWs can reach each other or the map is small enough that everything is in range of both SWs, regardless of where you build them. In the rare cases where it would make a difference, it is a nice strategic thing to consider; if you find your team being outranged, it is mostly because the guy building it did not check the range, if you build it just a little bit closer to the front, you can reach everything in the enemy territory and you are still mostly safe from enemy silos.
I would not underestimate the fact that DRP does not reveal its position. To scout a DRP, you need a competent teammate that plays airplanes and has a significant number of swifts readily available; very often, there isn't such a fleet of swifts available or the guy just does not scout, because he is too low-ranked, which means you cannot target it with a silo for 3+ minutes (until a competent played makes an airfac plate, builds swifts, scouts, and builds an appropriately positioned silo.
When DRP is stunned, it does not damage your team with falling meteors. And generally, once some location is protected with 3+ funnels and a bunch of shields, Zenith has a hard time damaging that location, you have to wait for like 2 minutes to gather enough meteors, and if there is even a wall, they might not work at all.
Despite those arguments above, I do agree that all in all, Zenith is now the stronger weapon - mostly, because it is much easier to use it to deal with paladins and detris, which means it helps your team to deal with the logical last-effort push from the enemy team (which often has a stronger army, if they did not build a superweapon). I would either suggest increasing DRP turn rate or raising the cost of Zenith to 40k metal as well.