This recent article by the BBC finally confirms something I have long suspected:
While writing in textese was significantly faster across the board, nearly half the students took twice as long to read messages aloud as compared to standard English versions.
In other words, the five seconds one saves by not spelling out words like “too”, “you”, “your”, “anyone”, “people”, etc. is quite possibly spent on the other end anyway by the person receiving the message who has to decipher it.
(While I do abbreviate in text messages occasionally, I limit it to words of seven letters or more or phrases with a relatively well known abbreviation.)