It's not really the meter so much as why do you need it?

If you really want pH, a testing lab can provide much more accurate results, and in some states it is a free service.

Moisture is best determined by the human finger (if the soil feels cool then it is moist), and light meters are important for orchids, but with roses a guesstimate is good enough.

well, i would agree with Hoovb re. the light meter and the PH meter but I have a moisture meter because I have hundreds of pots and it can be, if not a lifesaver, definately a plantsaver. Human fingers are OK if you have a few pots you want to check but if you have dozens, a little moisture metre is invaluable - and it can easily penetrate further into the soil than fingers and will flag up the dryness at the roots which is not always obvious when testing with a finger. Also, the wand is slender and will cause minimal root damage if you do need to poke it into the soil fairly deeply.
The PH readings on these metres can be unreliable and the light metre is fairly useless.

You can use the pH meter IF you're not looking for something precise, i.e. maybe you're looking for changes in pH rather than the actual value.

But, if you want to use the pH meter for actual readings, you should quality control it first each time you use it. I used our QC pH meter buffer at work (pH 7.0) and found my meter around half a log off (ie, buffer read 7.5 on the garden meter). Note that pH will not give you an idea of soil alkalinity.

Not to hijack the O.P.'s post, but I was wondering if anyone had their soil checked commercially and then compared it later with a garden soil kit, spa testing strips (which would include alkalinity) or also the meter. Of course a commercial lab is the gold standard, but if one were to use that as your QC reference when you get your results back and then use one of the above methods, you might have a method to do spot checking later on if you knew the 'error' of the other less exact methods.

Just a thought...