I have a Lotus TSP (well 2 actually, as I like the one I acquired with only 2 of the acrylic cover panels so much that I bought a slightly older one with the metal covers when I got the chance, intended for my granddaughter when she is older if she shows any interest in sewing). I sewed 8 sets of scrubs on the younger one during April and May. £40 was a very good price as they are sought after by quilters to take to classes and clubs etc.
Vintage Elnas are very pernickity about any little bits of thread caught in the bobbin area. My first TSP sewed much more smoothly once I had cleaned thoroughly, removing an inch of thread that I had no idea was there, and applied a couple of drops of oil to the oiling points. Apart from keeping them scrupulously thread free, it is recommended to hold onto both threads as you start a seam to avoid nesting underneath. I now do this for every machine that I use.