(Retired) vim-airline config - although it's great, it's just too slow and feels clumsy

airline.vim

" vim-airline
  Plug 'https://github.com/vim-airline/vim-airline'
  Plug 'https://github.com/vim-airline/vim-airline-themes'

  let g:airline_theme='bubblegum'

  " powerline symbols
  let g:airline_powerline_fonts=1

  " statusline settings
    " simplify line, col info:
    let g:airline_section_z='%p%% ' . nr2char(0x2630) . ' %l:%c'

    if !exists('g:airline_symbols')
      let g:airline_symbols = {}
    endif

    let g:airline_symbols.branch=nr2char(0x2387) . ' '
    let g:airline#parts#ffenc#skip_expected_string='utf-8[unix]'

  " tabline settings
    let g:airline#extensions#tabline#enabled=1
    let g:airline#extensions#tabline#show_close_button=0
    " smart file paths display:
    let g:airline#extensions#tabline#formatter='unique_tail'
    let g:airline#extensions#tabline#show_tab_nr=0
    " change labels:
    let g:airline#extensions#tabline#buffers_label=''
    let g:airline#extensions#tabline#tabs_label='TABS'
    " show buffer numbers (as shown in `:ls`):
    let g:airline#extensions#tabline#buffer_nr_show=1
    let g:airline#extensions#tabline#buffer_nr_format='%s '

  " extensions
    let g:airline#extensions#tagbar#enabled=1