There is a BIG difference in performance between some prop brands, APC gives you the best performance of all props while at the same time being the least durable and due to it's design the most dangerous.

When I started flying many years ago and didn't know the difference between props I always has a assortment in my flight box, as my supply would dwindle (all the same size) and I would change from one brand to another I could note a big difference between some brands (one being slower than the other) and eventually weaned out the weak ones to where I use mostly APC and Master A-S.

On the same note, don't buy cheap glow plugs, they too play a big part in performance AND longevity, Enya #3 and OS-F plugs as well as some others will cost you more but give you better and more reliable performance.

Use a nitro and synthetic oil based fuel, again, better performance AND better idle. Real castor oil makes a mess out of your plane, very hard to clean.