Pocket wifi, 75 or 21 mbps?

I'm going to rent a pocket wifi for my travels in Japan. Would a 21mbps wifi be sufficient or should I go for the 75? The price difference isn't that much anyway.

Things I intend to do: skype calls, google maps, bus/train route and planners, gps, stream some videos, games etc.

Is the signal strong when travelling on trains and buses, especially the JR shinkansen trains, going underground or in some areas like Mt Fuji, Kyoto and Hokkaido?
Do people encounter problems with its use?

Thanks.

If the price is the similar then go with the 75mbps especially since you intend to watch video. Where are you renting from? Some companies like Pupuru charge the exact same for either device.

Is the signal strong when travelling on trains and buses, especially the JR shinkansen trains, going underground or in some areas like Mt Fuji, Kyoto and Hokkaido?

Above ground buses and trains is generally ok. Shinkansen run quite fast and sometimes you may have poor connectivity due to constantly switching towers, but it's otherwise generally usable. Underground areas are hit or miss. Some are good, some not so good. Extremely rural areas may have poor coverage and often revert to slower 3g speeds.

Do people encounter problems with its use?

Yes, battery life is an issue. Consider getting a portable usb battery as a backup so that you don't run out of juice.

Several caveats:

The devices become very hot when in continuous use. If used in a purse, be careful of chocolates or medications.

Spare extended batteries for such devices are cheap and ubiquitous. Don't rent from them.

Transfers are throttled when you exceed certain limits. For instance, Global Advanced (a highly touted company that rents pocket wifi units) puts a max of 10 GB transferred data, after which the transfer rates are significantly reduced for the rest of the rental period. Some rental companies don't indicate this on their websites. Read the fine print.

Don't expect coverage everywhere. Check the coverage maps for your particular vendor, especially if you plan on travel in more remote areas. On the Shinkansen, with the numerous tunnels, you will lose coverage intermittently quite often.

Otherwise, personally, I find such devices very useful for travel. Others would disagree, I know.

Dale

Just to add:

Transfers are throttled when you exceed certain limits. For instance, Global Advanced (a highly touted company that rents pocket wifi units) puts a max of 10 GB transferred data, after which the transfer rates are significantly reduced for the rest of the rental period. Some rental companies don't indicate this on their websites. Read the fine print.

Global Advance, and all other companies using Emobile for their service (almost everyone who offers a 75 mbps LTE plan) have a 10 GB per month transfer limit before the speed are throttled to something like 150 kbps. Don't worry though, it is very tough to hit that limit, unless you are doing some big transfers or watching lots of movies while out and about which is an unlikely scenario. Try to limit those activities to when you are on hotel wifi. Services that use docomo as their backbone may have lower top speeds but generally no monthly limit. They may also be more expensive.

There are other providers out there, but these cover most services.

Don't expect coverage everywhere. Check the coverage maps for your particular vendor, especially if you plan on travel in more remote areas. On the Shinkansen, with the numerous tunnels, you will lose coverage intermittently quite often.

Definitely.

Otherwise, personally, I find such devices very useful for travel. Others would disagree, I know.

I think they are well worth it, especially if travelling with two or more people that need internet.

Thanks guys. Really cool info here.