I use Eclipse, that ROM only shows 3G. Not to worry about the icon, it is just cosmetic. The phone has the capability to get up to 14.4 HSDPA.
At the bottom of my build.prop, the area marked GSM SIGNAL IMPROVEMENTS, that would be the place to experiment with. I believe those settings are tweaked for 1900MHz. You may want to try some different hsdpa/hsupa categories. I do not know what it would be for 2100. I would probably wait for some other non-US users to chime in and see if they are also experiencing your reception issues.
Also, I am fairly certain flashing the XT860 radio will not work due to a signature mismatch. The XT862/XT883 are the exact same hardware, same signatures and everything. I believe the XT860 does have some differences.
Sony released quite a few of interesting devices in 2013. One … more
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