We have been very successful using Denx on PowerPC and use some thing from it on Arm/i.mx28. If you don't need hab, encrypted boot and a few other things and don't mind a slightly longer boot time its probably good and for sure less painful. If not you are likely stuck with the Rot that is LTIB. It is a constant barrier to productivity in our environment at some stuff is not trivial to extract from it especially when using HAB.
The penguintronix guys are great, they are the reason that the mainline works at all on i.mx28. Sure they will support you on the Freescale release but probably would not enjoy it.
We do i.MX work but hope you have gotten going by now.