Hi there,
Yes that’s a good observation on the Dev boards I have both just got the Nrf54L15_DK, both For the Jlink on board they work GREAT! with the SWD of Xiao.
Seeed is working on one as well so Hold off on the trigger pull until we see what they are going to release.
I started with the Nrf52840DK and it was the worth it for the Jlink alone, I have a REAL JLink and it was a gift (too expensive IMO) you need a couple adapters as well kinda Clunky but comes with Great software suite for other stuff to, so there’s that. I had a clone a while back , it worked but same situ with connectivity and for Updates I had to use a shoe-horn. 
Ah’ yes MCU boot for the Zephyr world , now your getting into a more pure Nordic dev environment in that direction.
That’s essentially correct. Here’s a breakdown of what that means:
- nRF Connect SDK (NCS) and Zephyr:
- Based on Zephyr:
The nRF Connect SDK is built on the Zephyr RTOS, which is an open-source, scalable real-time operating system for connected, resource-constrained devices. This modernizes development on Nordic chips. - No SoftDevice:
Unlike the older development approach that relied on Nordic’s proprietary SoftDevice (a precompiled binary for Bluetooth and other radio protocols), the nRF Connect SDK uses Zephyr’s native Bluetooth stack and other middleware components. This gives developers more flexibility and transparency since the stack is open source.
- Latest and Greatest:
- The move to Zephyr (and away from SoftDevice) is seen as a big step forward. It allows for a unified development environment, better integration with modern development tools, and often improved security and performance.
- In many ways, the nRF Connect SDK represents the future direction for Nordic’s ecosystem.
- MCUboot as the Bootloader:
- MCUboot:
MCUboot is an open-source, secure bootloader widely used in modern embedded systems. - Recommendation:
In the nRF Connect SDK ecosystem, MCUboot is recommended because it supports secure firmware updates and fits well with the modular, open-source approach of Zephyr and the rest of the stack.
In summary:
That is correct—nRF Connect SDK is indeed based on Zephyr, which means it doesn’t use the legacy SoftDevice but rather a Zephyr-based Bluetooth stack and related middleware. It’s considered a more modern, flexible, and open alternative. Additionally, MCUboot is recommended as the secure bootloader in this new ecosystem.
My order of devices,:
- Nrf52_Dongle (best $10) you will ever spend in the BLE dev world.
- PPK-II (best power profiler known to me, includes some very cool extras and is worth the $hondo…) makes battery and power assessments a snap!
- Nrf52840_DK ( a must have IMO if you don’t have a Jlink device.)
Nrf
Nrf54L15_DK (Early but I’m ready, but is Seeed
)
The free nrf SDK Academy courses, are the best you will find on the planet and they are FREE. should be #1 on my list. After a couple hours you can be up to speed and there forum is very good. They reply and suggest KNOWN working examples so no goofing around with old LIB’s and rolling BSP and all the NON-sence we sometimes go through with other MCU’s (bricks)
It’s Great stuff and a good time to get into the Development with all the tools and AI stuff. We are Lucky
HTH
GL 
PJ 