Mechanical disc brakes lacking stopping power I bought a carbon road bike about 4-5 months ago with Tektro Spyre dual pivot mechanical disc brakes.  Love the bike except for the brakes :( 

Brakes are not too bad on the flat but when going downhill with my hands on top of the drops, i have to use all my hand strength to stop and even then it doesn't stop straight away.

This is my first bike with disc brakes and I am wishing I didn't buy it.
The husband has the 'normal' brakes on his and they are fantastic. 

Options offered by a bike shop were - sell the bike and get a new one (love everything except the brakes about this bike and they're sort of important :)), change the brake pads and they would bed them in for me by riding the bike for hours, change the brakes to hydraulic.

Would appreciate any advice about which way to go here.  Obviously i am looking at the cheapest option first which is to change the brake pads.....thoughts???

Many thanks
Cath
I have TRP spyres and while I find they perform better than BB7's when properly adjusted, they are very sensitive to adjustment. They have a very narrow range between rubbing the disk and too far away for proper braking. You may have to put up with a slight bit of rub to get proper braking performance. 

While they are dual actuated[1] like hydraulic disk brakes, they are not self-adjusting. This means that as the pads wear the brakes need to be adjusted to compensate for the wear; it does not take much for these brakes to get out of adjustment. 

You will need a 3mm hex wrench to do the adjustment and if you are going to stick with this bike, I recommend that you learn to do it yourself. You need to adjust both brake pads on a regular basis. I've gotten in the habit of checking my brakes before every ride. They don't need adjusting every ride, but it something to watch. 

If that seems like more than you want to deal with, your options are to either switch to BB7's or a more expensive road hydraulic setup. BB7's work well and aren't nearly as sensitive being adjusted properly, but since they only have a single actuator they are not as easy to modulate. For a road bike that is much less of an issue than for a bike meant to function well on dirt. BB7's do require regular adjustment, but in my experience not nearly as much as the Spyre's. They also do not require a tool to do the adjustment. 

The last thing to check is that your TRP's are the proper model. Mechanical disk brakes often come in both Road and Mountain models that work with different pull ratios. Since these brakes were on the bike to begin with it's unlikely, but it is something to check. Look online at both models and look at the length of arm that moves the brake pads to determine if you have a road or mtb version.

[1]- dual activation means both pads move toward the disk, most other mechanical disk brakes have one fixed pad and one moving pad.