Alakazam would be a lot more bulky and powerful. If you had an Alakazam at level 100 and managed to max all of your stats, the stats would be this (Using a modest nature):
Special Attack: 405 (252 EVs, 31 IVs). At +6 it would be a whopping 1620
Attack (Bulk Up raises attack too): 122 (252 EVs, 31 IVs). At +6 it would be 488.
Defense: 126 (252 EVs, 31 IVs). At +6 it would be 504
Special Defense: 226 (252 EVs, 31 IVs). At +6 it would be 904
Although these stats seem too good to be true, remember Medicham has to set up without dying in 12 turns and then Baton Pass. Medicham is also taunt bait, as a quicker Pokemon could come in and taunt it, shutting the entire thing down. The high attack stat also makes Foul Play a much stronger move, further limiting Alakazam's potential with this. Although in theory this seems to be a good idea, it will most likely fail against any experienced player.
Hope I helped!