I am pretty sure I'm going to get the SP-1 and am probably also going to get the blackheart upgrade for it. If I get the blackheart upgrade, will this bolt help, and if so how helpfull is it to upgrade the bolt, and what exactly will it help with? (I'm new to paintball if you can't tell)
Blackheart > Virtue in this case. Blackheart comes with board, breach that has eyes, and QEV. Virtue has board only.
Blackheart will increase the max cyclic speed of the maker (QEV), give you tournament legal modes and more adjustability in your setup (Blackheart), and will give you a new anti-chop mechanism, the electronic eyes since with BH, you lose the low force bolt (due to the QEV).
As for the L7, I'd say get the Blackheart board and leave it alone. The L7 bolt IMO isn't worth the price. It's better than stock, but not enough to warrant it.
Bolt is lighter and slightly better design, so it will allow you to run lower pressure, lower dwell, while still cycling full speed. Thus decreasing the kick and increasing the efficiency of the marker. However, the actual gains are fairly minute.
i have a L-7 in my sp-1 and its pretty deng quite and i havent had any problems... my friend has a firebolt in his and that works really nice to... but if ur getting the L-7 dont pay full price i got mine on sale...