Either might work, as Albert posted this is no high precision instrument but is very useful.
I use the digital one paired with Chesky + stereo Review test CD (CHE151). Track 18 has a frequency sweep from 310 to 21 Hz.
Setting the SPL on a tripod at your listening position and having ready a sheet with the frequencies and a little patience you can s put the numbers you get on an Excel spreadsheet in your computer and then you can get a very nice room response map. You might need to play a little with the scaling since you might be surprised of the hills and valleys you might get.
This way you can see problem areas in your setup and work to improve your sound.
Also I used this with a 100 Hz tone to find a good place to place my equipment where you get less vibration induced by the sound in the room and has provided improvements.
I also use this to see effects like power cords and vibration control tweaks to cross check the compromises in improvements obtained vs losses.
There are other options out there for doing this and you can go as sophisticated as you like but with a little thinking you can do many things with not investing too much.
Happy listening
Regards
