It will be a good option to have in the arsenal, but is not obvious if/how many you can afford to run main
Gold Star Pokmon cards had an estimated pull of one per every two booster boxes
A few things I think could make this go from a 4 to a 5 are adding a "NEW" mark when you pull something you don't have, an actual numbered list in the sets to see the missing spots of your collections, and perhaps an actual incentive to ranking up your badge for each set
On paper the Primeval Titan seems a bit better with the trample, the card advantage and the ability for the game to get very out of hand however you need the support cards for Primeval and you need the right deck
For detailed pull rates and card breakdowns, see our Inferno X guide
Under this definition, the English Pokmon TCG contains between 15,000 and 18,000 unique cards