Already picked up my 2, yay!
Anyways, today's CotD is Porygon Z Promo DP35, which is a pretty fun card to play. Statwise, 120 HP is good, but still not average (130), +30 Weakness to :fighting: is a bit bad since Machamp is popular and likely will continue to get popular, no Resistance, and costing an ok :colorless:colorless to Retreat. Install is a nifty Poke-Power, letting you move around any TM you please; granted, there are only 2 TMs you can currently move around (TS1 and TS2), but hopefully that'll change soon. Learning is a great attack (even more so without an Energy cost), essentially acting as a free Level MAX; you get to level up any Pokemon you have in play (even on the bench). Overload is also a good attack; for :colorless:colorless, you deal 40+ 20 more for each TM on Porygon Z.
So of course, with Porygon Z, we must first look at TM TS1 and TM TS2. TS1 is great early game, letting you evolve your Pokemon quickly, and TS2 is decent for the late-game, letting you devolve 1 of your opponent's Pokemon (which, providing you weakened them beforehand, should KO). Now obviously, Install is still a bit limiting with the few TMs available, but you can easily stack on the damage, and playing more TMs is much easier than adding more Energy in a given turn. Plus, you still have the support of Porygon2 before evolving, which allows you to use and abuse Supporters by essentially playing an extra one per turn. Finally, you then have Porygon Z Lv X; Mode Crash promises to be huge since special energies are back en-force (even more so once SP Energy and Upper Energy arrive in Rising Rivals), and Decode still gives you a nifty option of getting 2 cards you need to the top of your deck. Porygon Z can even help SP decks; mainly, Porygon2 could be used here to abuse Cyrus' Conspiracy, and you can then evolve into Z to move around the future SP TMs that come out to different SP Pokemon (not Z himself sadly, since they'll be discarded if not attached to an SP Pokemon).
Modified - 8/10 (I think this has a lot of potential, and could do well, though if GE rotates next season, may as well say your byes now)
Limited - 0/10 (Can't really be used here since it's a promo, huh? And even then, you'd need to pull Porygon and Porygon2 from GE)
Unlimited - 1/10 (Not too much use, TMs here suck anyways)