In 1984, Spectrum is already 2 years old and starts to look obsolete when
compared to its competitors and the Commodore 64 in particular.
That's why Sinclair launches a new-look version of the Spectrum :
the Spectrum+ was born. 

In fact, it does not bring anything more apart from some cosmetic changes.
Concerning the keyboard, the rubber keys is replaced with a better keyboard
directly inspired by the QL keyboard, launched the same year.
If the keys are this time plastic made, the touch feeling is still a bit
too soft.
Fortunately, there is now a large spacebarre, arrow keys and new editing keys. 

Were also added two small feet under the keyboard, making it possible to
tilt the keyboard at a convenient angle for typing, a bit like on modern Pcs.
A small reset button was also added on the left-hand side of the case,
thus making it harder to accidently press it. 

In fact the Spectrum + largely adopts the look of the QL which is not
innocent at all, since apart from making the Sinclair product range more
homogeneous aesthetically, it certainly represented advantages concerning
the assembly lines. 

(www.old-computers.com)