I'll add a bit to my previous comment:
I compared negatives shot with a 150/4.5 Xenar, a 150/4.5 Apo-Lanthar, a 150/4.5 Heliar, a 150/5.6 Symmar, a 135/4.5 Eurynar, and a 135/3.5 Planar.
The Symmar was the most "neutral" of all those lenses, so that was the one I sold off. There was very little difference in sharpness, the main difference between the lenses was that the Symmar had more coverage than the others (I shot on 5x7" film in order to check the coverage as well). Since I also had 120/6.8 and 165/6.8 Angulon as well as a 180/5.6 Symmar, I decided I didn't really have that much need of the extra coverage of the Symmar over the Apo-Lanthar.
Last time I was out shooting 4x5" I brought 65, 90, 121, 150, 165, 210, 240 and 355mm lenses... Ended up using 90, 150, 165, 210 and 355mm. I keep bringing the 165mm for the extreme coverage (it covers 8x10"), but I would not have needed it if the 150mm had been a Symmar.
I would recommend you spend more money on the wide-angle lens - for architecture and interiors, you will need the coverage of a Super-Angulon or equivalent in 90 or 75mm.