plugin_customization.vim

let g:neocomplcache_enable_cursor_hold_i=1
let g:neocomplcache_cursor_hold_i_time=300
autocmd InsertEnter * call s:on_insert_enter()

function! s:on_insert_enter()
  if &updatetime > g:neocomplcache_cursor_hold_i_time
    let s:update_time_save = &updatetime
    let &updatetime = g:neocomplcache_cursor_hold_i_time
  endif
endfunction

autocmd InsertLeave * call s:on_insert_leave()

function! s:on_insert_leave()
  if &updatetime < s:update_time_save
    let &updatetime = s:update_time_save
  endif
endfunction

Nice job!