Read the fine print. There are always problems with reception, extra fees, contracts, and phone purchases. The "free web" for example might apply if you are within your home and connected to wifi, but out in the general community you may be hit with usage fees. Make sure the "free text" is for everyone, not just between the 2 of you.
I think all the services give you promises and then don't deliver. There's always some problem that can only be fixed if you upgrade or sign a new 2 year contract.
Also make sure that your Verizon charges don't include something else (e.g. internet, TV, etc.) that you would pay extra for if you switch. Bundling is a money saver, say the carriers, but not always.
You can try to get a senior person at T Mobile and have them look at your current bill (2 months worth) and tell you exactly what you would save with them. It will show them how you use your phones now. Of course they will try to switch you to their plan, but go through the itemized bill and write in the $39.88 next to the $140 Verizon charges you (and is that a base rate or the final rate after taxes, access charges, and extras are thrown in?), and then have the guy write down "0" next too all the other charges to prove that T Mobile won't do that. If there's a charge for activation, a new phone, etc., write those in so you truly have a "bottom line".
If you're on Facebook or have a good email listing of people in your neighborhood or work area, ask what their experience has been both at home/work or with travel.
Also find out if you can keep your same number and if there's a charge to upload all your current data to the new plan (contact list, etc.).