I use Glaze n Go for most of my clients and for those who don't want the gel top coat, I use the old fashioned way by reducing grits and then use a high shine buffer to get that lovely glass top finish.
I believe every tech should know how to bring L & P to a high shine by filing/buffing, I think you need to know how to do all these 'old fashioned' ways before going on and taking short cuts with other products, for example gel top coats, using an e-file but not knowing how to file or what the correct grit to use for the rebalance etc.
Could you imagine getting to the end of the service and finding you don't have any gel top coat left and having to tell your client that you don't know how to get a high shine any other way.....wouldn't look very pro would it