Speed is more than adequate on all models. It's not going to be your bottleneck, trust me. Not quite sure what you mean by "yours" but I don't own the Qidi (yet). The main diff between theEnder 3 V3 SE and Ender 3 V3 KE is the higher temp 300°C hotend, which gives you more freedom in choice of materials. Since they both are open frame printers without a heated enclosure, expect some warping when printing Polyamides. I'm currently quite successfully printing PAHT (high temp PA12) on my KE. Needs to be thoroughly dried first but no problems with warping so far. Surprised me, although the model's geometry might be partly responsible for that. In any case, dive right in, the water is warm. It's a great and sometimes very practical hobby, especially if you start to get into 3D modeling too.