I always use the luggage delivery service, I think it's one of the best things about traveling in Japan (among many). It's inexpensive, reliable and saves so much schlep! There are new rules for taking large luggage on the shinkansen, so I would definitely send it for those legs.
Our trip was Hilton Tokyo Bay - Kamakura - Andaz Tokyo - Universal - Conrad Osaka. We sent the luggage from TDR to the Andaz and took a carry-on for the 2 nights in Kamakura. Then sent it from the Andaz to Conrad Osaka and took the carry-on for the 2 nights at Universal.
Hilton Tokyo Bay has a separate counter for the luggage delivery and they charge a 500 yen/piece "hotel fee".

The woman there tried to tell me how to fill out the form, but I messed it up and asked too many questions, so she gave up and filled it out for me. Every single hotel I've done this at before filled out the form for me. One hotel last trip even called the hotel I was sending it to to tell them it was coming. So extra fee for worst (comparatively) service lol.
I wanted to use a locker at Maihama station after we checked out of the Hilton Tokyo Bay while we went shopping at Ikspiari. But all the big lockers were full except for a few hourly ones that required using an app. We didn't feel like trying to figure that out on the go. The big lockers should fit a carry-on plus 1-2 backpacks. I don't think they would fit checked luggage size.