Hi, I have 10 or 12 Kenmores from the mid-'50's through the '70's/early '80's and really appreciate their stitch quality and power. While I do not have the 148.1220 model you are considering, I have had the very similar 148.12070. I recently gifted this machine to my daughter's best friend because I thought it would be a very good machine for a new sewer who has a good coach in my daughter.
I downloaded a free manual I found on the 148.1220 (also covered the 148.1218 as well) and just finished going through it. The machine will sew straight stitch, zz, and two 'stretch' stitches from built-in cams. It had instructions for a "manual" blind hem stitch (three straight stitches, one zz stitch set on 3 stitch width, etc.). It is a Class 15, low shank machine. I did not see it in the manual but it probably has a 1.0 amp motor which is more than adequate piercing power as well as a probable left homing needle set up. I particularly like the extra space under the Kenmore presser foot.
All in all, I think it would be a good basic machine for garment sewing. I don't know if the left homing needle set up makes quilting a little trickier. If so, that needs to be verified. BTW, I really like Kenmores!