I bought this lightsaber to gut it and rip out the sound card.  For it's value, the newer Hasbro lightsabers (the thinner ones that come with the DVD) are actually MUCH MUCH better.  This particular lightsaber does the following:

LEDs flash / blink when clashing. There is only one swing/clash sensor and I think the board just alternates between the sounds.
The small additional lightsaber simply turns on and lights up, but does not have sound.

All in all, there are better (and actually cheaper) lightsabers out there - the newer ones cost around $20-25.  Plus you get a 15 minute DVD along with them.  Save your money for those. The boxes for those look like this:
<a data-hook="product-link-linked" class="a-link-normal" href="/Star-Wars-Electronic-Lightsaber-Obi-Wan/dp/B002WB17KW/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Star Wars Electronic Lightsaber - Obi-Wan</a>
<a data-hook="product-link-linked" class="a-link-normal" href="/Star-Wars-Electronic-Lightsaber-Darth-Vader/dp/B002WB17K2/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Star Wars Electronic Lightsaber - Darth Vader</a>