Those groks are quite old by now, and not impressive. Minimax M2.7 is a big upgrade vs 2.5, at a similar price, should easily beat the grok. GLM 5.1 is also a great value (with coding plans), around claude sonnet capability.
But if you are doing a lot of coding your best value will be a coding plan, not pay per token. Gpt plus is a really good value and its 5.4-high model is super capable, some even consider it better than opus.
I don't think it's worth getting less than state of the art models to do actual coding, if the code will actually be used. Costs a bit more but will save you a lot of time in the end, and will produce a better quality product.
For real work I'm already on Opus full time (plan+execute). I think there's a different space for cheap-but-good-enough options for small-to-med repo hobby projects. (Not enough usage to warrant a plan.) And Opus is only ~30 tok/s while grok-code-fast-1 is ~120. So planning with Opus and executing with grok-code-fast-1 is still on the table for me - it's good at following explicitly written plans, lightning fast.