Since I own both of these two boots I will give you a comparison of the two to help make up your mind....here goes:
Looks Asthetically speaking both of these boots look great in my opinion. With the Legends you have the more classic and simple look while with the Tunits you have the modern, cutting edge look. So in this department it is just a matter of preference. You might prefer one to the other, however this alone should not be the deciding factor.
Comfort Both boots are very comfortable right out of the box. This is a very important aspect for me as I am a firm believer in that boots shouldn't really require a lengthy break-in period. They should fit you great from the moment you buy them. If this is the case then you can be confident that they are the boot for you. Put another way, you could wear either of these two boots in the most important match of your life and not have to worry about foot pains or blisters. Playing on hard summer pitches is often a good measure of how comfortable a boot really is and I can safely say that both boots passed this test with flying colours. Not a single blister from either boot after full 90 minute matches with both - this in my opinion is very impressive taking into account the crap that manufacturers have been releasing in the last couple of years. One thing I will say is that the Tunits have more of an arc in the middle, where as the Legends are flatter throughout. Clearly, depending on your foot shape one may suit you more than the other.
PerformanceIn terms of touch the Legend is unbeatable. The whole boot (excluding heal counter and sole) is made from K-leather which is of very good quality. I have to give top marks to Nike here as they have avoided trying to put as little K-leather into the boot as possible (unlike the Pred Absolute of which about 40% is leather - signalling a huge backward step since the Accelerator and Mania which where nearly all leather). The only downside(s) of the Legend IMO are its weight and that it can take up a bit of water when playing on a wet pitch. However the weight for me is not such an issue as I am naturally a quick player and I don’t feel ‘slowed down’ as such in the Legends.
The Tunit is quite unique for a synthetic boot as the material is actually quite soft and you don’t get that horrible synthetic feel everytime you kick the ball. In terms of passing, shooting, crossing etc.... the boot is top notch (however like I said, the fantastic feel of the Legends is unmatched). Also you shouldn’t fall into the misconception that the Tunit is a light boot, as (with the comfort insole) it isn’t. Its main (and possibly only) advantage over the Legends is that you can interchange the studs as and when you like. Contrary to what many people have said, I have not had a single problem with the studs. I haven’t lost or broken a single one in roughly 15 games. What you have to make sure is that you tighten the studs before each match as they tend to loosen over time. Another advantage of the Tunits is that they are so much easier to clean.
OverallI have said pretty much all I can to help. However, you may end up going to the shop and finding that one is far more comfortable than the other. So make sure you do that if you can. If you are really keen on the unique stud mechanism on the Tunit then get them – they are not as problematic as people make them out. However, if you want a nice classic, comfortable boot that can do everything well then get the Legend…..you can’t go wrong either way.