I may not know the what is the average airspeed velocity of a laden swallow, but I know the average speed of adding a LOAD_METHOD opcode cache as in PR 23503 (measured with PGO + LTO + CPU isolation):

+-------------------------+--------------------------------------+-------------------------------------------+
| Benchmark               | 2020-11-24_18-08-master-0ec34cab9dd4 | 2020-11-24_19-41-load_method-0c43ca99644b |
+=========================+======================================+===========================================+
| pidigits                | 266 ms                               | 233 ms: 1.14x faster (-12%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| regex_v8                | 32.7 ms                              | 30.4 ms: 1.07x faster (-7%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| unpickle                | 17.7 us                              | 17.1 us: 1.04x faster (-4%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| scimark_sparse_mat_mult | 6.21 ms                              | 5.99 ms: 1.04x faster (-3%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| go                      | 283 ms                               | 274 ms: 1.03x faster (-3%)                |
+-------------------------+--------------------------------------+-------------------------------------------+
| mako                    | 20.4 ms                              | 19.9 ms: 1.03x faster (-3%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| pickle_pure_python      | 546 us                               | 531 us: 1.03x faster (-3%)                |
+-------------------------+--------------------------------------+-------------------------------------------+
| logging_simple          | 9.58 us                              | 9.34 us: 1.03x faster (-3%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| telco                   | 8.21 ms                              | 8.03 ms: 1.02x faster (-2%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| regex_effbot            | 3.97 ms                              | 3.88 ms: 1.02x faster (-2%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| regex_dna               | 267 ms                               | 261 ms: 1.02x faster (-2%)                |
+-------------------------+--------------------------------------+-------------------------------------------+
| pathlib                 | 21.2 ms                              | 21.7 ms: 1.02x slower (+2%)               |
+-------------------------+--------------------------------------+-------------------------------------------+
| xml_etree_iterparse     | 129 ms                               | 132 ms: 1.02x slower (+2%)                |
+-------------------------+--------------------------------------+-------------------------------------------+
| xml_etree_parse         | 186 ms                               | 193 ms: 1.03x slower (+3%)                |
+-------------------------+--------------------------------------+-------------------------------------------+

Not significant (46): scimark_fft; nbody; pickle; pickle_list; pickle_dict; logging_format; scimark_lu; deltablue; chaos; meteor_contest; sqlalchemy_imperative; scimark_sor; raytrace; scimark_monte_carlo; sympy_integrate; unpickle_pure_python; dulwich_log; logging_silent; nqueens; json_loads; crypto_pyaes; hexiom; django_template; sympy_str; regex_compile; sympy_expand; xml_etree_generate; unpack_sequence; spectral_norm; xml_etree_process; sqlite_synth; genshi_xml; pyflate; json_dumps; python_startup_no_site; 2to3; python_startup; genshi_text; unpickle_list; fannkuch; sympy_sum; sqlalchemy_declarative; chameleon; float; richards; tornado_http;