iOS7 and Safari are slow to respond when selecting <input> field and submit <button>. iOS6 and iOS4 are fine.
We are currently developing a responsive Bootstrap site using .Net. We are in the QA process for a few pages. Ever since the deployment of iOS 7 there is a significant time delay when interfacing with the page forms.
It takes 7 seconds for an <input> field to respond and the (cursor to flash within field), and 35 seconds for a Search <button> to submit query.
We do have one form where there is NO delay when touching an <input> or <button> field in iOS7. This happens to occur on a form that happens to be a plain Bootstrap modal “Contact Us.” This may be a fluke. There is one other plain Bootstrap Modal where delays do occur (Forgot Password Modal).
We documented the various scenarios where delays occur: http://screencast.com/t/HnBMaQAiDO
Behavior Note: The delay only happens on the first instance where that type of field is engaged; once an <input> or <button> on a page has been used and user has not left the page, activating other fields in the form is immediate.