>"Build a service/program to a spec via take home."
The problem with this is that the company has no skin in the game. Sadly flakey companies and recruiters are prevalent enough that it's not at all uncommon for a company to ask you to complete their "take home" assignment and then never get back to you. I've had it happen enough that I would simply refuse this now. I think if a company wants you to spend 3-4 hours on their take home project they should pay you for that time.
The problem with this is that the company has no skin in the game. Sadly flakey companies and recruiters are prevalent enough that it's not at all uncommon for a company to ask you to complete their "take home" assignment and then never get back to you. I've had it happen enough that I would simply refuse this now. I think if a company wants you to spend 3-4 hours on their take home project they should pay you for that time.