These are the results:

venv ❯ python -m pyperf compare_to json_old/* -G --min-speed=2 --table
+---------------------+--------------------------------------+------------------------------------------+
| Benchmark           | 2021-01-14_09-40-master-14cfa325c298 | 2021-01-14_10-39-slotscache-9123a84ad8d4 |
+=====================+======================================+==========================================+
| float               | 148 ms                               | 133 ms: 1.11x faster                     |
+---------------------+--------------------------------------+------------------------------------------+
| pidigits            | 265 ms                               | 252 ms: 1.05x faster                     |
+---------------------+--------------------------------------+------------------------------------------+
| scimark_monte_carlo | 130 ms                               | 126 ms: 1.03x faster                     |
+---------------------+--------------------------------------+------------------------------------------+
| spectral_norm       | 168 ms                               | 164 ms: 1.03x faster                     |
+---------------------+--------------------------------------+------------------------------------------+
| logging_silent      | 221 ns                               | 216 ns: 1.02x faster                     |
+---------------------+--------------------------------------+------------------------------------------+
| sympy_expand        | 598 ms                               | 585 ms: 1.02x faster                     |
+---------------------+--------------------------------------+------------------------------------------+
| regex_v8            | 31.9 ms                              | 32.6 ms: 1.02x slower                    |
+---------------------+--------------------------------------+------------------------------------------+
| deltablue           | 8.93 ms                              | 9.16 ms: 1.03x slower                    |
+---------------------+--------------------------------------+------------------------------------------+
| unpickle            | 17.0 us                              | 17.7 us: 1.04x slower                    |
+---------------------+--------------------------------------+------------------------------------------+
| Geometric mean      | (ref)                                | 1.00x faster                             |
+---------------------+--------------------------------------+------------------------------------------+

Benchmark hidden because not significant (50): sympy_sum, sqlalchemy_imperative, sympy_str, sympy_integrate, dulwich_log, scimark_fft, genshi_text, tornado_http, regex_dna, sqlalchemy_declarative, mako, meteor_contest, unpickle_pure_python, xml_etree_parse, genshi_xml, scimark_sor, sqlite_synth, pickle_pure_python, nbody, pickle_dict, pyflate, regex_effbot, xml_etree_process, logging_simple, python_startup, 2to3, fannkuch, python_startup_no_site, raytrace, go, hexiom, scimark_lu, json_dumps, richards, logging_format, xml_etree_generate, chaos, telco, pickle_list, unpack_sequence, regex_compile, django_template, json_loads, crypto_pyaes, xml_etree_iterparse, unpickle_list, nqueens, chameleon, scimark_sparse_mat_mult, pickle
Ignored benchmarks (1) of json_old/2021-01-14_09-40-master-14cfa325c298.json.gz: pathlib


I uploaded the pyperf result data to bpo as well