If keeping the owner occ loans long-term and moving on to the next deal(s) as owner-occ, you will run into tougher guidelines on your 5th property and then you are cutoff from conforming financing after your 10th (as was mentioned above. 

As far as finding good handyman this can be tougher.

The only downside is that the loan and the property has to be in your name at the time you apply for financing and you can only have 4 loans in your name (including your personal home, vacation home ect) at one time before the terms change and get a little tougher to qualify for.  

You have to provide notice before entering unless it is an emergency.Seattle is far tougher on property owners than the Walla Walla area.

Plus the tougher lessons stick with you for a lot longer. 

Are you purchasing in the tougher areas?

That's going to be a tougher area to rent up even if the numbers match Neil's numbers above. 

Over the past 12-18 months the acquiring at 30-50% of value is now more around 50-70% which makes it much tougher to get in and find a good deal.

although if you competing against true cash buyers this is a little tougher as well.. but you need your pre approval letter and POF to accompany your offer day one .. 

Am I tougher for earning that masters degree?