So I though I would post my findings about the galaxy s3 reception. I chose an area where the reception was weaker (moderate coverage) than surrounding areas for both CDMA/EVDO and LTE.
I would like to bring something up before giving my results about the open signal maps app and other dbm info. The dbm information reported by these apps and the system info is the dbm of only the cdma signal. I found this out when using *#*#4636#*#* on my rezound (or using the network app in market instead of the code for latest ICS for rezound) to change the network mode to LTE only. On HTC at least, this setting disables the CDMA radio and the signal bars go to 1 tiny bar, but 4g is still lit up. If you try to check the dbms or signal, its the same as you would see if there was no service. Calls also cant be made. I have not yet found any app that can monitor the LTE strength, its like its either on or off. With WIMAX, you had a separate 4g icon with wifi type signal indicator. If anyone knows of a monitoring tool (Or can make a MOD like the WIMAX reception indicator!) let me know.
I compared the S3 stock ICS, Incredible 4g stock ICS, Rezound 3.14.605.10 ICS, RAZR ICS
I measured dBm from the setings menu and used speedtest.net app and speakeasy.net/speedtest in stock browser.
dBm
S3=-117
Rezound=-80
Incred 4g=-75
RAZR=-95
Speed Test Avgs (3 app results+3 browser results=total/6=avg)
S3= 2.48 down 1.79 up
Rezound= 13.68 down 5.48 up
Incred 4g= 14.2 down 5.61 up
RAZR= 8.61 down 4.32 up
As far as the amount of bars, its not a great measurement tool, so I am just gonna rate it by volume of the bars filled.
S3=less than 1/4 full to a 1/4 full
Rezound=Half to slightly over half full
Incredible=Half to slightly over half full
RAZR=Half to slightly under half full
Im not sure whats up the the S3, but may be able to be fixd with an update I hope. I think the HTCs just have a benefit with the antenna being in the back cover. The original incredible had TERRIBLE reception, but since the Tbolt, its been much more improved. I would think the S3 should at least be on par with the Razr.