Hi Jason,
You must have already decided by now, but this might still be interesting to others.
I've been using SearchMetrics Essentials quite a while now and I really like it. The features I use for all my clients/prospects:
- SEO Visibility: graph composed of search volume on ranking keywords. Great for prospects, especially in comparison to their competitors (and to measure basic optimization impact).
- Position Spread: shows on which positions a site ranks with their keywords
- Long-tail keyword rankings based on their crawls of the site. This means SearchMetrics shows you relevant keywords with rankings, search volume (calculated by SM) etc.
- Competitor Analysis with all above features
- Subdomain / subdirectory analysis (SEO visibility), however you can't really digg in with Essentials
The price for Essentials is fine in my opinion: $69 p/m. However, if you want to have some extra functionality, like digging into subdomains/subdirectories, projects or integration of Web Analytics, you need the Suite, which will cost you $399 or more. Off course, you'll get a lot more features. But for my business, this gap is way too big.
Personally I'd love a SearchMetrics version without projects, social, backlinks and ppc but with the possibility to digg into SEO-stuff like subdomains and directories plus Web Analytics integration. At about $200 p/m 
My advice to anyone would be to try Essentials. It just has some great functionalities that tools like Moz just don't (like SEO Visibility).
Remko
