same here. gpt-5.x medium was my default for coding and v4 flash (max) has completely replaced it. it's the first open source model that made me feel like I could just let rip and not worry any more than Claude or GPT.

When planning small-to-medium sized changes, I found that it was a little bit faster than GPT-5.5 (high) and produced equivalent results. on large changes its results were fine but GPT's were more thoroughly thought through. DS v4 beats the absolute pants off GPT when it comes tone and style though.