Depend on division - Majors is great, SBS is good for experience but not a career
Pros
The difference between divisions is staggering. Small Business Services is a great place to get your initial sales experience, learn to sell and make some money, but it's heavily micro-managed, intense and unsustainable as a long-term career (for most, especially if you're not able to develop strong referral relationships.) Major accounts has the support and tools you need to sell value and great opportunities for making a lot of money. ADP adapts to the marketplace (albeit sometimes a little slowly) so you can meet client needs.
Cons
Trending a little towards mico-management since the recession. Many of the DVP roles are filled by executives from SBS who have a "matrix-mentality." Love tracking. Not all bad, but can interfere with selling time. Your experience can really vary by region and depend on the manager you work for.