It's a shame how some idiots decided NOT to save those Decade card sounds so they were forced to get the guy back and record new ones. But surely the guy (whatever his name is) remembers vaguely the tone of the announcements. Some like 'Advent', 'Gigant', 'Metal', 'Gaga no udewa' are supposed to have relatively high pitch voice are now completely low tone and don't match at all. Also for some reason the announcements went very Japanese Engrish style, e.g. 'Blasto', 'Cho Climax' etc. The Diend sound is also slightly different. It's also inexcusable seeing how Slash and Blast were used in Climax Heroes series.
However it's great to have the BGM, especially the fact that it changes as soon as you insert the card. The Form Rides were mainly similar to the show, love the new sounds for the Heisei Rider Final Forms. Overall a good addition, hopefully the Diendriver will be equally great as well.
Also there are some leaked sounds already, including Wizard with his henshin sound, Delta with a Diend summoning sound.
EDIT: It seems like they never bothered saving the sounds once the series ended. After rewatching a few scenes in the show, the original 'Clock Up' sound was used in Ep 1, 18 and All Rider VS Dai Shocker. Movie Wars 2010 had a different recorded sound. Then by the time Super Hero Taisen came round, they didn't even bother with it and used Kabuto's Clock Up and Clock Over instead. The Invisible sound however was still accurate in Rider Taisen so I don't understand why they recorded a new one.
I guess it explains why Decade barely uses cards that the original DecaDriver doesn't have in movies after MW 2010, because the sounds aren't there, so they go for new cards instead (Gigant, Side Basshar, Advent, FFR Double, FFR All Riders). If you noticed, in these movies Decade tends to just use the Kamen Ride cards, fight in that form and that's it. Even in Wizard's last episode, he could have used FFR All Riders, but instead just used Kuuga and Agito. I guess this has got to do with the lack of saved sounds as well.