I just went through this a few weeks ago. If you look in the Product Review section, you will see my thread which will give you quite a few good ideas.
With that being said. I just ordered 1 four shooter with standard sound Bumper Boy. I will most likely order more later, but here is my reasoning of why I chose Bumper Boy over Thunder Launchers.
1. Price. You can order a 4 shooter for $1036, which includes the transmitter and receiver. You can then order additional ones for approximately $900, which includes the receiver to work with transmitter you got with the first one.
I personally like the Thunder500 Launcher and wanted so bad to go with that model, based solely on how compact it was. The one thing that stopped me from doing it was the cost. It is $1000 for one, and does not include transmitter, which is another $300. So, it is $1300 (approx) for the first one. Then, if you want to order a second one, it is still $1,000, plus another $175 for the additional receiver.
Comparison in Price. Two 4 launchers of Bumper Boy is under $2,000. Two 5 launcher Thunder500 is just under $2,500.
I do see that Bumper Boy now offers a receiver that is compatible with all launchers that use Tri-Tronics or Dogtra remotes, so I may venture to buy a Thunder500 in the future and get the bumper boy compatible receiver, but anyway you look at it, it is still $300 more expensive for each consecutive unit of Thunder500 than Bumper Boy.
This analysis in now way indicates that either product is good or bad. As I said. I really like the compactness of Thunder500 and also that it is enclosed and will launch in all conditions, but Bumper Boy loads have problem when working in wet conditions, so that may be something else you need to consider.
Good luck. I can not wait to get my Bumper Boy order and try it out, hopefully during the Thanksgiving weekend.
Doug