transportation from Heathrow

Price and time - you got it.

The Heathrow Connect doesn't go all the way to / from T5. So you would need to change trains at T1 & 3. This pushes the time for the journey up to 43 minutes.

Marco, is it an easy transition hauling luggage?

Everybody else - other than those who packed light and just have carry-on - on the same route as you will also have luggage. How much will you have?

Have you ruled out a car service? Neither Heathrow Express nor Heathrow Connect are handy unless you are staying near the Paddington Station terminus. If there are two or more of you traveling, a car service will be about the same price as the Heathrow Express with transportation directly to your hotel and minimal luggage hassles. simplyairports.co.uk and justairports.com are regularly recommended. Many others to choose from. The tube is faster than the Heathrow Express to some London destinations at a fraction of the cost. I don't recommend the tube if you can not carry your luggage some distance and up stairs.

We only have one piece of luggage each but we are two old ladies who prefer not wasting our energy hauling luggage. We are close enough to Paddington so we have focused on train transport for that reason. I think for that reason, all things considered, we will go for Express. Thanks everyone for your comments. As usual, they have been helpful