Well my 34L arrived today, and I'm really impressed with it. I've been busy and hadn't had a chance to read all the comments until just now! I am going to shoot my standard real estate stuff without the centre column and take note of how often I may want to nudge the camera up just a little to improve composition. If it's a regular occurrence then I'll order the column, if not, I won't bother. I did consider getting a heavier tripod with geared column, but my equipment is already heavy enough as it is and the 34L is impressively light. Knowing how much it weighed and then feeling it in hand. I was actually quite surprised how light it feels. It feels rock solid, and I think it will do the job just fine, as well as being good for other jobs that I will use it for including portrait and landscape work. Everything is a compromise in one way or another. As for overkill, I'd like to be shooting high res medium format digital in a couple of years if all goes well, and I had that in mind when deciding between the series 2 and series 4.
Anyway, thanks for all the replies
I do have an issue though, but I'll create a new post for that.