Hi King_fisher IMHO, it really shouldn't do you any harm to submit via the submission service, but
You will get better results doing it yourself
You will probably not get much traffic from the directories themselves,
If your site is an affiliate site, the majority of established directories will probably reject your site immediately,
You will probably get a few acceptances, and if the directory is nurtured by the owner, then your link from that directory might become worthwhile within six months
However, if your site is definitely an adwords/affiliate site, perhaps you should consider using paid advertising options straight away
cheers