Are you in the US or UK? I have not heard the Shadow range but the Apex are just fantastic - they really are. If I did not have a size restriction, I would have got them without a doubt. There are a very high number of satisfied Apex users in the UK who love them to bits.
Only caveat is to to get a different sub as better value can be had for less - if you are in the US, then an ID brand like SVS, PSA etc would be ideal. Hope that helps!