On the 323 I think I would be concerned about crevis corrosion on the chain plates for the shrounds. The sealant job looks sketchy at best and has probably been that way for a long time.
Although looking at the boat I think if you could get it cheaper than what its listed for it may be worth purchasing it
The tartan looks good over all but it looks like the joint at the stub and keel is cracked - I would be concerned theres some water intrusion to the keel bolts (but i very well could be wrong and who knows what the bottom of the pearson looks like)
The tartan needs new running rigging
After looking at both boats - Unless you could get the pearson for an insanely low price and a survey doesn't find any hugely expensive problems with it - I would go with the Tartan - It looks like its been maintained a hell of a lot better than the Pearson