Also of value has been
Thesaurus.com - put in key words from any clue
Universal Anagram Solver
Anne Stibbs - Crossword Lists/Crossword Solver
But as to TEA, its much better than any online solver, many of which have only been available in the last few years. Check out the solving features on the website.
It cost about £25 and has solved anything I've thrown at it. Its definitely paid for itself over and over again in prizes I've won.
Its also solved other peoples questions on here and AB which other solvers have failed to manage.
Its up to you, but I'd heartily recommend it.