What's Worse - 404 errors or a huge .htaccess file

[CleanEdisonInc]

We have changed our site architecture pretty significantly and now have many fewer pages (albeit with more robust content and focused linking).

My question is, what should I do about all the 404 errors (keep in mind, I am only finding these in Bing Webmaster tools, not Moz or GWT)?

Is it worse to have all those 404 errors (hundreds), or to have a massive htaccess file for pages that are only getting hits by the Bing crawlbot.

Any insight would be great.

Thanks

[twitime]

I think the 404 errors would be more of a concern.  A large .htaccess shouldn't be a problem especially if you are only talking about a few hundred redirects.

[customerparadigm.com]

It's not ideal to have such a massive .htaccess file that it slows down your page load time significantly.  But if you have a lot of inbound links to pass that matter, you'll likely want to keep your SEO value intact and use 301 redirects to handle this properly.

My $0.02: Test!

Do a page load test with the .htaccess file off / removed, and then do another one where it is on and live.  If there's no significant time difference, you should be okay.

We have sites with hundreds or even thousands of lines in the .htaccess file and they run pretty quickly.

That said, here's why 404 pages aren't ideal to serve:

According to Rand Fishkin's Moz blog writeup, Are 404 Pages Always Bad for SEO?
http://moz.com/blog/are-404-pages-always-bad-for-seo

"When faced with 404s, my thinking is that unless the page:

A) Receives important links to it from external sources (Google Webmaster Tools is great for this)
B) Is receiving a substantive quantity of visitor traffic
and/or C) Has an obvious URL that visitors/links intended to reach

It's OK to let it 404."

According to Moz's Redirection SEO Best Practice:
http://moz.com/learn/seo/redirection
... you want to use a 301 redirect to indicate that the content has moved permanently.

Finally, here's a post that describes how to create a more SEO friendly migration, here's a great info graphic:
http://moz.com/blog/achieving-an-seo-friendly-domain-migration-the-infographic

Hope this helps!
Thanks,
-- Jeff