Speaking in Tongues

At the Bank Holiday weekend at the end of August we were encouraged to speak in tongues for 10-15 minutes every day until the Sheffield meeting (which is next week now).
I have tried to do this, but not always managed it, and it has varied from being a slog to being an amazing experience.

Someone once said that speaking in tongues too much was not a good thing 'cos it only built yourself up and did not help the body.
That seems to be an odd thing to say 'cos surely the more inspired members the body has, the more healthy it is?
The more used we are to getting in touch with our spirit and with the Holy Spirit the more we will have to contribute to corporate spiritual life.

Another time someone else said they liked to pray in tongues 'cos it is a heavenly language, given by God, so whatever you pray in tongues must be in the spirit and must be the right thing to pray for the occasion 'cos it is God's words you are praying!

Anyway, I was thinking about the discipline of all praying in tongue, and about how much power it must be having in the spiritual realm. It reminded me of when all the people of Israel went marching around Jericho everyday for a week, until on the last day they gave a big shout of praise and all the walls fell down.
I don't know for sure, but I would expect it took a bit of discipline and commitment to get everyone to do the marching, in silence, once around the city every day for 7 days, and then 7 times around on the 7th day.
The people must have had faith in God. Human nature would have grumbled and shuffled chattering around the city, and maybe not bothered to get out of bed after the third morning doing the same thing yet again.
The other thing was, on the 7th day, when Joshua gave the command to shout praise, they were ready, they were expectant, they shouted for the glory of God and when the walls came down they were ready to go in and take the city as God commanded.

So, when we have finished praying in tongues as God has asked us.... what are we going to see God do at Sheffield? Are we ready to shout for the glory of God, to see the strongholds fall, and take the victories God has in store?