I'm already dismissing the Capbots. Like somebody said first, it makes for a great novelty item - Just not something most of the series/era specific collectors may want.
With Optimus Prime... I am currently done with PRIME. Arcee will most likely be my only Arms Micron piece, as she has rightfully earned her spot within my collection. But this piece is very interesting, even though it has a slight variation to Iron Man's color scheme.
"Masterpiece" Soundwave... He is a different case. I had gotten the original as a birthday gift when I was a kid. To this day, I still think he is one of the best toys out there. So much that I wish I could have gotten his "Encore" version in 2007. And he is the reason why I ended up getting "Encore" Soundblaster. So when it comes to him, lets just say that my heart yearns for this piece... And it hurts that it will not have that yearning be answered. (In other words, he has my highest recommendation - TIED with Grimlock!)
And finally "Masterpiece" Alert. For the longest time, I was disputing him. I felt that having a "Security Officer" within my collection would be fun. But now... I think the fact it is promoting Lamborghini has me thinking I will not get him. However, I do recommend him to fans of Generation 1 and car enthusiasts. And for those here... If you have Lambor, get him. That way if they make the others, or not, you'd have a nice set-up going on (either way).