I use Tcl::Tk on a regular basis and really happy with this.
After some 10+ years of usage of this approach - I understood that this is the perfect balance of simplicity and power for my GUIs.
Nicer GUI libs often require more efforts during coding, so I haven't switched to these.

often I use pure Tcl CPAN module instead of Tcl::Tk, because I rarely actually need that perl/Tk syntax,

$int->call($widget,'method','submethod', -smth=>'val');
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is quite enough, so perl/Tk syntax is an overkill

$widget->methodSubmethod(-smth=>'val');
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given that most my GUI code is separated already into some place...

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