Hardly impressive, TinyCore linux is 17mb, 23mb if you want a basic gui

Free RAM for LTSB for PC with 4GB: 3.3 GB
Free RAM for LTSC 1809 for PC with 4GB: 3.1 GB
Available RAM for LTSC 2021 for PC with 4GB: 2.9 GB
Free RAM for W11 Pro Edu December 2023 release for PC with 4GB memory...2.4-2.5GB...

For all version Defender is switched off and block for start.

LTSB is almost as fast as W7 Pro, response loss is no more than 5-10%.
LTSC 2021 minus 10-15% performance.
W11 Pro Edu minus 35-40%.

W11 can be tuned according to the taskbar to the W10 version plus the bonus of an analog clock (the patch does not require root access) from W7. W10 does not have the bonus of an analog clock from W7.

W8+ (all editions do not have the classic theme (Pro class) from W7. Which immediately puts an end to well-packaged UI for the classic theme (W95+) from W7.

In fact, the professional compact interface disappeared from Windows with W8, i.e. all versions including Enterprise have essentially become for housewives, not professionals.

The only way to return the classic compact theme to W11 is to roll out a patch to system dlls, which violates the integrity of the system. But that doesn't stop some.

In fact, M$ never brought W11 to a stable state - they do not have an LTSC version for W11. There is still no classic professional theme (or the ability to customize the sizes of 3 buttons in the window and everything else as the owner needs).