Haven't tried campaign monitor. As for Mail Chimp, I like it very much. Loads of intergrations lately with other services, if that is any useful to you. Also like the easy calls to action for social media outlets (e.g. Tweet this). Pricing is reasonable. Embedable forms are OK. If you need a pop up sign up form you won't get it (for the moment), I've tried AWeber for that.
Stats are very good and they have an "inbox inspection" feature which lets you correct possible errors before sending out the campaign.
Mailchimp is a good system. More features and options then Campaign Monitor and is updated often. All these tools are pretty similar at covering the basics of sending, managing and tracking.
As for better? It depends on what you want to do. If you have something specific in mind i can recommend a suitable tool for you.
Yea they're great - lots of resources on their site ( blogs/tips/tutorials etc ) .... i dont know about reasonable prices though, but that's a matter of opinion --- it jumps from free for the first 500 to 30p/m for the next section - and it goes up from there..... maybe it's cost effective for a larger number but 30pm for 501 contacts is pretty steep compared to the market average if i got my research right at the time ( about a month or 2 ago) - i've moved from mailchimp to phplist for that reason, but i dont think phplist could beat mailchimp for reporting etc..... also they do a pay as you go option which might suit some.