I've played with them for a while on PBE I'm a jungle main and I've been playing since 2009. This is my opinion if anyone cares.
The plants aren't bad however, they aren't good and are defiantly not a good replacement for smite buffs here's why.
To start with they don't really have any negative impact on the game so it's not like it's a bad thing. A main concern from people was the RNG of plants I can firmly tell you the RNG is not a problem at all. There is honestly nothing wrong with them.
However, they have little to no realistic use in game. I find myself using the the blast one never for running or "plays" the only use I get from it is hitting it behind me just to micro manage movement speed to other areas. The healing plant has never saved me. The only use I find for them is just to pick it up for some health and mana just to make jungle clears easier/quicker or have a somewhat safer health pool if a fight breaks out. The vision one is the only somewhat useful one, it's nice to get vision of people but it also tells them I know and where I am as well so most the time it doesn't do much for me. I like the ward vision aspect back on them from smite buffs that is useful.
Now to explain why smite buffs are far superior. The plants as a whole just feel like they have no impact on the game at all. I honestly love smite buffs so much more as a jungler it gives me something that is unique to the junglers. We have the power to get ward control, use the wolves smite to gain vision in both sides of the jungle. Destroy towers faster with the use of kruggs buff and get some some extra damage back to enemies with gromp.
It feels like a whole other element to the jungle to save smite or not and what I should smite in different situations. This has been the same since they came out and I have never got tired of it. In my opinion it was the best change to the jungle ever. It added more depth to counter jungling with it big time.
To sum things up, I think you should maybe work more on evolving smite buffs instead of removing them for plants. But, to add a final note the changes to the camps adding raptors, removing the side monsters with blue and red, and making the kruggs split is awesome.