I used SWE-1.5 and 1.6 when it was Windsurf (before Devin Desktop), it's not that bad (grunt work, tests, can actually plan and implement some medium level stuff) but you get a much much better value and better models (GPT-5.4^) going with a Codex subscription (plus you get resets).
That company truly subsidized its user base to the extreme before, the $15/mo subscription was the best value on Earth paired with weekly deals reducing credits for premium models. Now it's barely any messages for paid models, completely watered down.