I lost DR space and need to downsize from a 6x7 enlarger to a Durst 600 or 601. I'm exploring buying a like new M601 used primarily for 645 negs. Anybody have the M601 baseboard and column height dimensions? The M600 and M601 differences I see from pictures are head cosmetics, the column, and provisions for a red under-the-lens filter. Any other improvements between the M600 and M601? Any user experiences?