Setting font weight in Terminal.app for El Capitan
Starting in OS X El Capitan 10.11, Terminal's font smoothing is reduced for light-on-dark text, so that the overall weight is closer to the weight of dark-on-light text, improving readability by opening up counters (the open spaces inside glyphs like “e”), for example.
You should find that it matches Safari's text rendering for light-on-dark text. It addresses the issue referred to in the question you linked: Is there a way to make the terminal's font less blurry?
This new behavior is automatic and doesn't read the AppleFontSmoothing preference.
If this is important to you, I recommend filing a bug report asking for either Terminal's new behavior to honor the AppleFontSmoothing preference or to add a Terminal-specific preference to control font smoothing.
Update: As of macOS Sierra 10.12, this behavior has been tuned to not reduce the font smoothing as much for light-on-dark text, matching Safari/WebKit more closely, and it does not apply at all to Retina displays. In addition, it once again honors the AppleFontSmoothing preference, making the smoothing lighter relative to the AppleFontSmoothing value. The end result is that the weight of light-on-dark text should look as close as possible to the weight of dark-on-light text with the same AppleFontSmoothing value.
You can change the font, however, it appears to be a font smoothing issue. I just upgraded from Yosemite 30 minutes ago and notice a HUGE difference with the terminal font I've chosen (Menlo) and how it looks now.
It's not as simple as just tweaking the sizing and weight as it's now being rendered differently on a system level. There may be a way to change smoothing back to how it was prior to the upgrade for the Terminal, which is the only issue