Poor performing XML feed in Ruby on Rails (3) application

Using Ruby 1.8.7, Rails 3.1.11.

We have an XML feed that is performing badly. The main table it is not very long (~13,000 rows) but it is very wide and we are eager_loading 9 associated tables to get the data needed in one (or 2, Rails seems to do 1 query to get the ids, and then another with a WHERE IN clause?) query.

There are quite a lot of nodes for each entry in the response (~40), and there is some logic involved (mostly display-related, url_for, one call to enconde64).

When hit the feed with a request that produces 380 results, i'm getting:

Completed 200 OK in 11187ms (Views: 9897.7ms | ActiveRecord: 1252.1ms)

which seems a bit excessive in terms of both View-related and AR-related time.

When i remove all the nodes in the XML output except for the main object ID, i get:

Completed 200 OK in 2543ms (Views: 1945.3ms | ActiveRecord: 507.9ms)

This cut the time down quite a bit, which i suppose argues for digging into those nodes to try to track down time killers?

But isn't almost 2 seconds to iterate over 380 records an indicator of another avenue of investigation needed?