No..
You're monty is much stronger. The mad is just a saracen with a different geo, but the point is its a saracen.. saracens are certainly not some of the strongest bikes around.
I gather youre wanting to upgrade from your monty but still keep it cheap? If you are and you want something that is cheap but rides very nice, perhaps look into the base ta26 a little more again as I know you were a while back. Although strength could again reflect in price.. but bases are stronger than sacarens.
If you are wanting something longer then you are probably going to have to pay a little more..
I understand that there are many very nice looking and very nice riding frames about right now, and some of them are a little pricey.
Best bet is to keep the monty a little longer and perhaps save up some more money a little longer and you could buy something that will ride soo nice and also be very strong and stiff.
The monty certainly can't be limiting you.. I have seen some amazing riding on an urban so trust me, it's not making you a bad rider.
Sam :-