^ If the MJ2 is at all like Lyr, those NOS tubes will improve a lot on stock.
Different tubes are likely to have a marked effect. Congrats and look forward to your impressions.
Yes tube rolling does improve the overall sound of the MJ2. I have rolled the following tubes. Telefunken E88CC Platinum tubes, Telefunken TK's, Gold Lions, and NOS EDISWAN. All those tubes sound good in the MJ2. My favorite tubes are the NOS Telefunken E88CC Platinum tubes. But for everyday day use, I use the current production Telefunken TK's.