One minor nuance to be aware of: When you embed Marketo forms, there is a slight chance that some people/respondents are able to bypass the required fields. Although the amount of times this happes is very few, it does/will happen. We found that outdated browers and Macs were able to override required fields when embedded using iframes. Something to keep in mind especially/know about embedding.
I think the other thing to consider when evaluating embedding vs. marketo pages is the user experience. If you're keeping them on your website (IE when they access the asset, they're not leaving your webpage) then it makes more sense to embed. However, if they're being directed to a Marketo landing page after filling out the form, the user experience was better sending them to a Marketo landing page first. We experienced higher conversion rates embedding and keeping them on our website, but that was when we discovered that some people were able to bypass the required fields. When we switched some pages over to Marketo landing pages, we experienced a slightly lower conversion rate, but didn't lose any lead information in the process.