Should I bother installing Sp5a, or just plan to move ahead to 4.1 SP2? I wanted to wait on BES v4.1 to see how it went for others, and it seems like it hasn't been too bad.

I would assume that the upgrade to 4.1 is much more complicated than applying service packs, so does anyone have any advice or tips?

Thanks in advance.

My upgrade from 4.0.4 to 4.1 was flawless, but I didn't install the MDS Services stuff, either (which is where most seemed to have their troubles). You should be fine with 4.0.4, as 4.0.3 is the required level for upgrade.

I had no issues running up from 4.0.4 to 4.1 - like jibi I too didn't bother with the MDS Services.