What kind of harm there is from removing (purging) package apt-xapian-index?

I know you can't use Quick filter in Synaptic after purging apt-xapian-index, but is there something more severe?

I know there are some performance issues, when you have it:

• https://bugs.launchpad.net/apt/+bug/363695
• https://bugs.launchpad.net/ubuntu/+source/apt-xapian-index/+bug/655831

There isn't anything severe. You might lose some functionality (see the description below), but if you don't need it, you can remove the package (just be careful it doesn't uninstall any other packages). If you later find out that it was a mistake, you can install it back again.

Description: maintenance and search tools for a Xapian index of Debian packages
 This package provides update-apt-xapian-index, a tool to maintan a Xapian
 index of Debian package information in /var/lib/apt-xapian-index, and
 axi-search, a command line search tool that uses the index.
 .
 axi-cache allows to search packages very quickly, and it also interfaces with
 the shell command line completion in a smart way, providing context-sensitive
 keyword and tag suggestions even before the search command is actually run.
 .
 update-apt-xapian-index allows plugins to be installed in
 /usr/share/apt-xapian-index to index all sorts of extra information, such as
 Debtags tags, popcon information, package ratings and anything else that would
 fit.
 .
 The index generated by update-apt-xapian-index is self-documenting, as it
 contains an autogenerated README file with information on the index layout and
 all the data that can be found in it.

I've removed it because on an eight year old computer it could at times cause a good hangup. Haven't noticed any ill effects.

It is a known bug, but it seems that no problem arise removing it:

update-apt-xapian-index bogs down system

Probably setting nice to 15 and ionice to idle for apt-xapian-index process could solve the hanging issue.