Once Locke has been blocked, changing its power or the power of the blocking creature won't cause Locke to become unblocked
They both also synergize nicely with Miirym, Sentinel Wyrm and Reflections of Littjara (which is already included in the deck), as you'll get activations off both your original creature and their clone
He can disrupt the opponents hand while simultaneously building up a board presence
So, I start every deck at 40 Lands (and these days, frequently, 10 mana ramp spells for a total of 50% mana in my decks)
There was definitely a period of time where I noticed my play patterns with the card were actively sabotaging my land drops later in the game, and during the early days of Commander, where big, splashy spells were king, I wrote Land Tax off as being more trouble than it was worth
Whoever wins that mini-match gets to tutor up any two cards they like from their deck a pretty powerful reward for the hassle