The only drawback is how much more work those are compared to a contemporary ski.
Hot wax em, or get em hot waxed and you will be fine...
In addition to reassuring you that they will release and that no plastic parts have gotten brittle and will break, forcing a bunch of releases will spread around any remaining lubricant a bit. This sort of test is crude, but its better than doing nothing, and the price is certainly right.
Tom / PM
How much more difficult is it going to be to ski on these longer guys?
This is a subject of intense debate amongst skiers, so you are likely to hear a lot of highly polarized opinions on this.
I consider myself in the middle in this debate. I've skied for around 30 yrs and switched over to "shapes" a few years ago.
I would never go back and seek out a classic "straight" ski for purchase, but if someone put one in my hands, I would have absolutely no hesitation skiing it under the right conditions. In fact, I take my old ultra-stiff, ultra-straight (ie, 60 meter sidecut radius) 207-ish Volkl Zebras out once or twice a season just for fun, even though I have modern skis ranging from 12 m sidecut SL's to 30 m powder boards in my quiver.
Softer, more deeply sidecut skis are going to be *MUCH*, **MUCH** easier to handle in deep, very heavy snow and spring slop (once you develop the appropriate technique).
OTOH, on the much more common hardpack and on light fluff that you can push away, if you mostly make classic skidded turns, the difference in effort required between old and new skis is much smaller (IMHO). The "shapes" are still easier, but maybe only by 10's of percent if I had to put a number on it and your were a good skier on the old equipment.
Finally, I should comment that since its so easy to generate high-G's while carving on modern SL's and hypercarvers, (again, IMHO), its sometimes more taxing to ski on them (because its hard to resist the fun of these types of turns), than it is to ski for the same amount of time doing low energy, low-G skidded turns on long straight skis.
Bottom line - use your old skis the same way you did 13 years ago and have fun. However, if it looks like your return to the sport is going to be permanent, demo some of the new equipment, and most importantly, take a couple of lessons on how to best use it.
Just my $0.02,
Tom / PM