As you said +damage + health, but really? No.
Use your Lab only to upgrade units that are really effective considering their effectiveness/training time. Use samples if you have a level 10 Cantina. I have hundreds of gamo samples, rarely I use them.
SWC Windows survivor.
Imperial HQ 11 & Rebel HQ 11 on vacation. Currently in "Giveandgettroops" (Level 50 Imperial Squad) and "SevenOfNine2" Level 50 Rebel Squad -- training squads, everyone is welcome!