I use hugin for stitching. I process raw files with minimal adjustments, exported to 16-bit TIFFs and import those into hugin.
If your shots align well, you can use the automated options to get good results in a few minutes for typical 4-shot pano's. If your images do not align well, you can be in for extended tweaking in expert mode to get useful results. Most folks probably don't try to solve the problems when the automated alignment process fails, but I do. I wouldn't describe the learning curve as easy.
Hugin can estimate optimal output resolution based on input images and overlap, so you don't have to. The time for a typical alignment of images in automated mode will vary strongly with the number of images, because each image will be compared to every other image. So two images can align in seconds and twenty images may take many minutes. Rendering times scale linearly with the number of images and resolution. A typical 3 or 4 image sequence @20Mpixels aligns in less than a minute and renders within a couple of minutes for me. YMMV.