shared hosting/reseller accts and blacklisting

Hi,
first time posting...please forgive me in advance for my lack of terminology and/or inaccuracies below...

I'm looking at Hostgator and one of your strong competitors. I'm most familiar w/ conventional shared hosting but think I'll have to go the reseller route. I have about a dozen sites that need to be moved from an existing hosting company. the main issue I've had with them recently is a huge issue w/ blacklisting, which has affected everybody's email (they are all add on domains).

I noticed some information here describing HG's recent outgoing email IP initiative that cuts down on blacklisting by changing around the outgoing IP address.

Can anyone comment on its success/failure so far? Thanks in advance.