I personally have owned a TM Vsr10-Gspec, upgraded with a 130 spring. I personally was not impressed with its stock performence, and with the 130 spring installed, it impoved its fps (obviously), but i still was not impressed. I may have gotten one of the few tm lemons out there, but overall if you have to choose from one of those two guns go with the aps. To answer your question, Yes spring guns do get harder to cock when you mod them, and there really is nothing you can do about that. As for the trigger pull if it does get harder with the upgardes there is a knob that you can turn to adjust the trigger pull to make it lighter or heavier (a nice little touch).
I typically do not bash tm because 10 of my 15 aeg's (not counting gas or spring guns) are TM, and not one has given me a single problem.
Personally i would have to suggest the tanaka line of sniper rifles. I am personally looking at a tanaka m24 sws as one of my christmas presents. Tanakas have been chrono'd at 400-500fps stock, most of the later tanaka rifles provide pcs (pressure control system which lets you control the fps of the gun, a nice feature to have). The tanaka line of sniper rifles are famous for a light and precise bolt action movement. Granted they are gas and they do not care for cold weather all that much, but it didnt stop one of my friends from giving me a nice battle scare on my thigh during last winter at (around 150ft, never again will i just leave a leg popping out
) You most likely live in canada since this is "airsoft canada" were i live in USA virginia. It does get cold here, but not as cold as it gets in canada (thats why i go skiing in canada, or in colorado only
).
Overall i suggest lookign at the tanaka line of sniper rifles, but you really cant go wrong with the aps either.