Acquia - Lock-in Risk?

Just received an email from the Real Story Group warning followers about the risk of being locked into Acquia's web hosting services.  Here's a link to their web page containing similar content:

www.realstorygroup.com/Blog/2908-Be-wary-of-lock-in-with-Acquia

Here's the text I'd like to discuss:

Today, Acquia offers hosted products for:

• Search

• Behavioral personalization

• Multi-site management

• CDN

• And more on the way...

Note that unlike a standard Drupal module you could swap in or out, these products bind you to Acquia. There is no formal community around them, save your fellow customers.  With some exceptions you can only use them in conjunction with Acquia's own cloud service, based on its own distribution of Drupal.  In short, these products mimic offerings from a commercial software vendor.

Taking each one of these products individually:

Search - Acquia uses Apache Solr, a free, open-source product.  There's nothing keeping you from implementing Solr yourself.  No lock-in.

Behavioral personalization.  I believe Acquia provides this service separate from its hosting service.  So even if you moved your Drupal site to a new IaaS provider (or your own data center), you can continue using this service.  No lock-in.

Multi-site management.  This is a core Drupal capability.  If you take your Drupal implementation elsewhere, you can still implement multi-site management.  No lock-in.

CDN.  CDN services are incredibly easy to implement - and replace.  I see no lock-in here.

Maybe Acquia provides some service/services that actually do increase your risk of lock-in, but nothing on RSG's list seems to have any relevance here.