The question is specifically about the Orc Bloodine. At level 15, you get a free "Giant Form I" spell:
Power of Giants (Sp): At 15th level, you may grow to Large size as a standard action. At this size you gain a +6 size bonus to Strength, a –2 penalty to Dexterity, a +4 size bonus to Constitution, and a +4 natural armor bonus. You may return to your normal size as a standard action. You may remain in this size for up to 1 minute per character level per day; this duration does not need to be consecutive, but it must be used in 1 minute increments.
This is cool and exactly the kind of hulk-like sorcerer build I'm going for. However, there is clearly a better version at just the next spell level called "Giant Form II". The only difference I see is how you can turn it on and off at will and save the minutes, and doesn't need a material. Why doesn't it upgrade to form II at some point?
Do you think it's fair that I "upgrade" this power to the second version if I take Giant Form II as a sorcerer learned spell? I'm not trying to be overpowered, I'm trying to get use out of my bloodline power for more than just a few levels. In fact, I'll have the Giant Form II spell either way.