I'm using the same setup as yours and I place the antenna indoor. previously with just e398 I could only connect to DC HSPA+ with a very congested tower. so during normal time, I could only get between 500kbps - 1mbps at best. no chance at all for hd YouTube.

yesterday I bought this antenna and spent a good half an hour hunting for the best spot to get LTE because with e398 alone I could only detect a fading signal. luckily I found a good spot where it detected 2 bars and after testing, a stable 5-7mbps connection. I know it's far cry from the real LTE speed but if you consider the nonexistence of LTE at my place according to both telco's website and their customer service rep, this is an excellent result.

to make sure the modem didn't drop the connection to 3g, I've set it up to connect to LTE only in MDMA. so far everything is well. I'm a happy customer thanks to a great item & service from blacktubi. thumbs up!