Instruction: Given the user's review, identify the user's sentiment from the listed options. Answer using one of the options.

Input:
EDIT - the humidistat stopped working during the 2nd season of use. I would now rate this 2 stars.

This is an excellent humidifier, especially for the price. It's very quiet. A filter typically lasts almost an entire season here in dry Arizona (usually October til April or whenever we turn the swamp cooler back on). It keeps our 3 back bedrooms humidified nicely just as long as you don't open the windows of course. I only fill it up every other day at most during driest times (outside humidity = 9% today!)
The only reason I give 4 instead of 5 stars is that the humidistat failed after 3 years of use. From my experience with these types of units 3 years is pretty good service and at this price it's really fantastic. I'm about to purchase another one...

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: B: positive