Hotel or apartment in Interlaken?

Hi,
I read in one of the posts that one of the travellers has booked an apartment in Interlaken. For 5 night stay would be good to rent an apartment? How does one verify the quality and security aspects then?

Current my plan is as follows:
Day 1 Early morning - Zurich to Zermatt
Day 2 Late afternoon - Zermatt to Lucerne
Day 3 Early morning - Mt. Titlis and back
Day 4 Early morning - Lucern to Interlaken. Then visit Trummelbach and Gimmelwald the same day.
Day 5 - Whole day Jungfraujoch.
Day 6 - Bern half day and local Interlaken sighseeing upon return.
Day 7 - Interlaken to Lausanne by scenic route via Zweisimmen-Montreux.
Day 8 Early morning - Lausanne--Zurich--Salzburg, Austria.
Day 9 and Day 10 - Salzburg, Austria
Day 11 Early morning Salzburg--Zurich. Local sightseeing in Zurich and then fly back.

In this plan would it be better to book 5 nights in Interlaken and skip Lucerns altogether? In that case on day 2 I can go from Zermatt to Interlaken and and day 3 cover Mt. Titlis from Interlaken.

Thanks.