Is it me or does their freedom line seem not as good as the VX2 it replaced? Debating on changing all the deer rifles from Nikon pro staff to VX freedoms.
You're looking at the bottom of the barrel. There's no justification to replace an existing scope with a manufacturer's entry-level scope that is specified to appeal to a consumer who has no scope at all and cannot afford the better choices. To see an improvement over Nikon quality, I would expect it to come with the VX3-HD line that recently replaced the VX3i. However, if there is any improvement, it would be subtle. A move from Nikon to VX3 would be closer to a parallel move than a major upgrade. These level "3" scopes have not "gone downhill" but have kept consistent with Leupold's quality level for decades now.
One thing to note is that these scopes have since the Vari X-III adopted turrets suitable for "dialing" with laser rangefinders. The VX3i line had only some models equipped with the CDS-ZL turrets. With the VX3-HD line, the CDS turret is ubiquitous.
The "3" is indicative of the optical power ratio. For example, a traditional 3-9x40mm has a multiplier of 3. 3 times 3 is 9. As you know, riflescopes brought to market in the most recent decade have stretched those multipliers to 5x 6x 8x and even 10x or maybe more. So we have 3-10x50 and 1-8x25 etc.
You didn't mention what Prostaff models you have. Are they 3X variables? Do they have dialing turrets? Do you dial?
With relatively lightweight optics, SFP reticles, MOA-incremented CDS turrets, and magnifications suitable for game at typical distances, Leupold's VX5-HD and VX6-HD product lines are well suited for deer hunting and a scope in these lines would be a definite upgrade to an older Nikon. To be sure, in this price range, there are considerable alternatives from other brands.
The one scope that doesn't have much competition is the Leupold FX3 6x42. This fixed-power scope has outstanding optics that I do not believe can be beat with any other $400 scope or even any $800 scope. It's very light, not very long or bulky, and reasonably rugged. It's not an ultra long range scope or a combat optic, but if 6x is an appropriate magnification for where the hunting is done, and the hunter uses MPBR or simple hold-over, I think it's one of the best scopes under $1000.