Like all the other users above, I too, am looking to move my lists to another provider if "ADD MEMBERS DIRECTLY" is not reinstated! I manage several lists with almost 1,000 people and have over 50 now waiting to be added. Important information is emailed on several of these lists daily and it's having a definite negative impact on our ability to function in the way we have in the past.
The easiest solution to the spam probem is to have more than one owner/manager to moderate messages and keep spam out. By using this method, I have NEVER had spam get through so it is NOT a problem.
I have been promoting googlegroups to many other people but will retract my recommendations if this is not corrected. If there is no change back soon, I will start moving my lists, too.